Foamed composition for pavement patching, and methods of utilizing and producing the same

ABSTRACT

A low density annular grout composition for filling voids. The composition may consist of cementitious fly ash, water, set retarder and cellular foam. The composition may have a compressive strength of between 100 and 600 psi at seven days and less than 1500 psi at 28 days. The composition may have a density between 20 and 75 pcf. Also disclosed is a method of filling a void with a low density annular grout composition. The method can include determining the time necessary to fill the void, adding water and set retarder to a cementitious fly ash to make a wet mixture, adding air to the wet mixture, and adding the composition to the void.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/149,542, filed on May 31, 2011, now U.S. Pat. No. 8,882,905, whichclaims priority to and is a continuation-in-part of U.S. patentapplication Ser. No. 13/112,793, filed on May 20, 2011, now U.S. Pat.No. 8,747,548, which claims priority to U.S. Provisional PatentApplication Ser. No. 61/395,956, filed on May 20, 2010, U.S. ProvisionalPatent Application Ser. No. 61/395,930, filed on May 20, 2010, and U.S.Provisional Patent Application Ser. No. 61/455,604, filed on Oct. 25,2010. This application also claims priority to U.S. Provisional PatentApplication Ser. No. 61/396,482, filed May 28, 2010, U.S. ProvisionalPatent Application Ser. No. 61/458,630, filed on Nov. 29, 2010, U.S.Provisional Patent Application Ser. No. 61/458,861, filed on Dec. 3,2010, U.S Provisional Patent Application Ser. No. 61/464,547, filed onMar. 7, 2011, U.S. Provisional Patent Application Ser. No. 61/462,978,filed on Feb. 11, 2011, and U.S. Provisional Patent Application Ser. No.61/464,546, filed on Mar. 7, 2011

INTRODUCTION

The present disclosure generally relates to using fly ash as acementitious ingredient in compositions. Using fly ash, a by-product ofcoal-fired electric power production as a substitute for Portland cementhas many social benefits for sustainability as fly ash is a 100%recycled, post-consumer product. Further, no additional carbon dioxideis produced, no additional natural resources are mined and no additionalfossil fuels are used. By contrast, the use of Portland cement requiresapproximately 3500 lbs of mined resources and fossil fuels to produceeach ton of cement. In addition, the avoidance of carbon dioxidegeneration by using fly ash creates carbon credits, which adds economicvalue to any given project.

The present disclosure provides compositions and methods for fillingsurface and subsurface voids with cellular, annular grout comprisingcementitious fly ash. Annular grout is historically a Portland cementcomposition for use in filling subterranean voids, i.e., areas around anunderground pipe. Typically, access to the void is restricted, suchthat, the composition for filling the void must be pumped into the voidwithout direct access to the entire void. For example, annular grout istypically used when replacing an older underground pipe with a new pipeby slip-lining the old pipe with a new pipe.

Compositions for use as an annular grout must have sufficient fluidityfor pumping and subsequently filling voids without requiring anycompaction. Compositions for use as annular grout must also have adelayed set time to allow the grout to flow the length or width of thevoid without setting. Compositions of the present disclosure exhibitsufficient fluidity for pumping, set-times for extended durations ofinstallation, yet sufficiently high strengths at the required lowdensities.

In another embodiment, compositions of the present disclosure alleviatethe frost-heave typically associated with backfill composition andreduces ice lens formation. Generally, to manipulate undergroundutilities or for equivalent reasons, an operator must excavate the areaon top of and surrounding the work site to gain access to theunderground area of interest. Following manipulation of the area ofinterest, e.g., water pipe or sink hole, the excavated area will bebackfilled with a composition that promotes subsequent use of thesurface as quickly as possible. For example, when the area of interestlies beneath a road surface crucial for a city's traffic pattern, thetime from excavation to reopening of the road is critical. The downtimefollowing repair is directly correlated to when the backfilled surfacewill support the anticipated use, i.e., vertical loads from routinetraffic or compression from pavement structures which withstandsubstantial loads.

In addition to the downtime associated with said repair, one must alsoconsider the longevity and integrity of the backfilled area. Often, evenwhen downtime is minimized using specific compositions, the samecompositions are subject to facture cracking during compaction of theasphalt allowing subsequent ice lens formation during freeze thawcycles. The ice lens formation within the backfill drives thebackfill—and surface pavement covering said backfill—up as the icelenses freeze and expand. This results in an uneven surface and the needfor further repair to the backfilled site. The resulting uneven surfacealso damages the shovels of city snowplows and causes general damage tovehicles subjected to the uneven road surface.

U.S. Pat. No. 5,106,422 (the “'422 patent”) discloses a backfillcomposition including a minor amount of cementitious Class C fly ash andother filler materials in a major amount. When such materials arecombined with water, they produce a backfilling material. Thebackfilling composition of the '422 patent ranges in amount from about 2to 10 parts by weight filler material to about 1 part by weight Class Cfly ash with sufficient water to react with both Class C fly ash andfiller material. Problems have been encountered with the formulations ofthe '422 patent, and new compositions are necessary to solve theseproblems.

For example, freeze-thaw vertical heave of pavement patches is a commonissue with current '442 patent backfill compositions. Severalinvestigations in regions having freeze-thaw temperature zones havediscovered the freeze-thaw vertical heave of pavement patches is due tothe formation of ice lenses in the horizontal cracks of current backfillcompositions. The creation of these horizontal cracks results from thecompacting of asphalt patches overlying the backfilled void and/or postplacement excavating and patch installation. The compacting of asphaltpatches is necessary to achieve the correct density.

Most agencies require the type of pavement repair material be the sametype and thickness as the original pavement, to achieve compatibilitywith the trench repair. In some cases, agencies also require a T-patchwhere the surface area of the patch is larger than the trench backfillsurface area. Some installers and municipalities have stopped usingcompositions of the '422 patent because of frost heave problems. Mostroadways are constructed of asphalt paving materials; hence mosttrenches are repaired with asphalt paving materials. To achievelong-term durability of the trench patch, the asphalt must be similarlycompacted to normal specifications (often to 92% to 96% of thetheoretical maximum density). To achieve these densities, mostcontractors utilize their steel-wheeled compactors in vibratory mode,not static-mode.

However, typically, the strength of the backfill material near thesurface is not sufficiently strong enough to resist the horizontal shearstresses caused by the compactive mechanism, e.g., rollers, resulting inhorizontal compaction fractures.

When water infiltrates these horizontal cracks and freezes in coldweather climates, the entrapped water expands vertically by around 11%of its volume/thickness. Thawing allows more water to infiltrate the newcrack volume, which then expands around 11% during the next freezingcycle. Repeated freeze-thaw cycles during a winter can create individualice lenses up to ⅜ of an inch or more. The heave of the pavement patchat the surface is the sum of the thickness of these ice lenses formedabove the local frost depth, and can be up to 3-inches above theoriginal pavement surface or more.

The compositions and methods of the present disclosure alleviate theencountered problems. Namely, the present disclosure alleviates thefrost-heave typically associated with previous backfill and reduces icelens formation. The compositions and methods of the present disclosurealso provide a more homogenous mixture, e.g., the high air contentcontributes to fluidity and reduces gravity segregation; therebypreventing the flotation of carbon particles to the surface andresulting in weakened planes for early freezing or compactive cracking.

The compositions and methods of the present disclosure also provide acomposition with a lower modulus of elasticity that is more forgiving &less-brittle during compaction; thereby decreasing the likelihood ofhorizontal crack development. In addition, the present disclosureidentifies methods for determining and using compositions that reach acritical compression strength quicker, maintain a lower removabilitymodulus (“RE”), prevent water from becoming trapped within thebackfilled composition, expedite backfill mixture optimization, andprovide more predictable and repeatable laboratory procedures, mixdesigns and testing methods.

The present disclosure further provides a composition that reduces thebackfill composition setting time; thereby reducing the time to pave orpatch and resulting in a total reduction in time from the start ofbackfilling to a return to normal use.

In addition, the present disclosure also discloses a high-performancecomposition, generating high strengths, suitable for replacement oftraditional concrete in specific applications of building construction,and methods of using the same. The present disclosure further includescompositions made of 100% recycled materials that will achieve normalstructural requirements normally achieved with Portland-cement, andmethods of using the same.

The present disclosure further provides a masonry grout composition forfilling cores or cavities in traditional masonry construction, andmethods of using the same. The present disclosure additionally providesan economical, easy-to-install composition for use as wicking layerunder concrete slabs, instead of the general industry recommended layerof compacted crusher fines, and method of using the same. The presentdisclosure also further discloses a composition for use as a moredurable temporary pavement patch than traditional “cold-mix” asphaltproducts currently in wide use, and methods of using the same.

SUMMARY

The present disclosure identifies a low density annular groutcomposition for filling surface or subsurface voids comprising between30%-85% air by volume; between 50%-90% cementitious fly ash by weight;between 10% and 45% water by weight; and between 0.01% and 2% setretarder by weight, wherein the composition has compressive strength ofbetween 100 and 600 psi at seven days, a compressive strength of lessthan 1500 psi at 28 days, and a density of between 25 and 75 pcf. Insome embodiments the composition my further comprise a filler.

The present disclosure includes a method of determining a low densityannular grout composition for filling a void comprising identifying atleast one fly ash for use in the composition; determining a water demandof each fly ash within the composition; calculating a water demand forthe composition; determining a compressive strength for the composition;determining the amount of air content necessary for the composition tohave a compressive strength of between 100 and 600 psi at seven days, acompressive strength of less than 1500 psi at 28 days, and a density ofbetween 20 and 75 pcf; determining the time necessary to fill the void;and determining the concentration of set retarder necessary to delay thecomposition from setting before the void is completely filled.

The present disclosure includes a method of filling a void with a lowdensity annular grout composition comprising determining the timenecessary to fill the void; adding water and set retarder to acementitious fly ash to make a wet mixture; adding air to the wetmixture, wherein the composition has a compressive strength of between100 and 600 psi at seven days, a compressive strength of less than 1500psi at 28 days, and a density of between 20 and 75 pcf; and adding thecomposition to the void.

The present disclosure also reveals a high-performance backfillcomposition, generating higher early strengths yet still sufficientlylow ultimate strengths, at the same time improving freeze-thawdurability and reducing the occurrence of frost-heaved trench patches.In an embodiment, the present disclosure achieves these goals bypurposely including air content for a new and improved cementitious flyash composition for backfilling voids. In an embodiment, the amount ofair content created by varying cellular foam additions can be optimizedfor the ultimate strength gain desired, the performance of specific flyashes used, and the ambient temperature during the backfilling process.

In an embodiment, compositions and methods of the present disclosuregenerally solve problems with frost-heave in backfilled voids resulting,mostly, from ice lens formation. Compositions and methods of the presentdisclosure prevent problematic compaction fractures, which allowfrost-heave, by determining the strength needed to resist compactionfractures to depths of local frost penetration. Once this strength levelis determined for specific equipment & procedures, various compositionscan be utilized to achieve this strength level in time frames desired topatch and open the roadway to traffic. Different strength levels can beused below the depth of frost-penetration and/or influence of compactionequipment, thus optimizing the overall economics of trench backfill,subject to the desired time constraints.

Interestingly, testing shows that time to set is a function of the freelime concentration in a blend of cementitious and non-cementitious flyashes or other fillers, and the water/fly ash ratio, but essentiallyindependent of the amount of air content, e.g., from cellular foam.Hence a faster set time can be achieved with more blends using morecementitious fly ash and lower water/fly ash ratios, while the ultimatestrength can be limited with higher amounts of air content.

In an embodiment, a composition of the present disclosure includes acomposition for preventing ice lens formation comprising from 5% to 70%air; from 5% to 90% cementitious fly ash; and from 5% to 70% water,wherein the composition has a compressive strength of between 10 and 60PSI after 4 hours and a removability modulus of less than 1.8 after 28days. Additional compositions can include a filler from 5% to 80%.Unless otherwise stated, all percentages of compositions are weightpercent based on the final weight of the composition including theweight of water and air. The exception is that all percentages of airare based on volume of the final composition as defined in the DetailedDescription.

In an embodiment, a method of the present disclosure includes a methodof determining a composition to prevent ice lens formation comprisingdetermining the water demand of each fly ash within the composition toachieve a desired fluidity; calculating the water demand for acombination of fly ashes; determining the compressive strength for thecombination of fly ashes; and determining the amount of air contentnecessary for the composition to have a compressive strength of between10 and 60 PSI after 4 hours and a removability modulus of less than 1.8after 28 days.

An alternative method of the present disclosure comprises a method ofbackfilling a void to prevent ice lens formation comprising mixingcementitious fly ash and filler to a predetermined ratio; adding waterto the mix of cementitious fly ash and filler to make a wet mixture;adding air to the wet mixture, wherein the predetermined mix ofcementitious fly ash and filler, the addition of water and the additionof air makes a composition having a compressive strength of between 10and 60 PSI within 4 hours and a removability modulus of less than 1.8after 28 days; and adding the composition to a void.

The present disclosure also further comprises in an embodiment, acomposition for caisson construction comprising between 0.0001% and 10%air by volume; between 60%-95% cementitious fly ash by weight; between5%-30% water by weight; and between 0.01% and 2% set retarder by weight,wherein the composition has compressive strength of between 3000 and5000 psi at seven days, a compressive strength of between 4000 and 8000psi at 28 days, and a density of between 100 and 150 pcf. Additionalmethods of utilizing and designing compositions for caisson constructionare also disclosed.

In an embodiment, the present disclosure further comprises a compositionfor construction comprising between 0.0001% and 10% air by volume;between 60%-95% cementitious fly ash by weight; between 5%-30% water byweight; and between 0.01% and 2% set retarder by weight, wherein thecomposition has compressive strength of between 3500 psi and 6000 psi atseven days, between 5000 psi and 10,000 psi at 28 days, and a density ofbetween 100 and 150 pcf. Methods of utilizing and designing compositionsfor construction are also disclosed.

In an additional embodiment, the present disclosure further discloses arecycled composition comprising between 0.0001% and 10% air by volume;between 15%-35% cementitious fly ash by weight; between 5%-15% water byweight; between 50%-80% recycled filler and between 0.01% and 2% setretarder by weight, wherein the composition sets in less than 4 hoursand has a density of between 115 and 150 pcf. Methods of utilizing anddesigning recycled compositions are also disclosed.

In an embodiment, the present disclosure further discloses a masonrygrout composition comprising between 0.0001% and 15% air by volume;between 70%-95% cementitious fly ash by weight; between 10%-30% water byweight, wherein the composition sets in less than 40 minutes and has acompressive strength of between 100 and 500 psi after 1 hour and 2500and 6000 psi after 24 hours. Methods of utilizing and designing masonrygrout compositions are also disclosed.

The present disclosure further provides a wicking composition comprisingbetween 45% and 80% air by volume; between 70%-90% cementitious fly ashby weight; and between 10%-30% water by weight, wherein the compositionsets in less than 4 hours, has a compressive strength of between 100 and600 psi after 7 days and has a density of between 20 and 60 pcf. Methodsof utilizing and designing wicking compositions are also disclosed.

In an embodiment, the present disclosure further discloses a compositionfor patching a trench comprising between 70%-95% cementitious fly ash byweight; between 10% and 30% water by weight; and between 0.01% and 2%set retarder by weight, wherein the composition has compressive strengthof between 150 and 450 psi in 1 hour, a compressive strength of between600 and 1800 psi in 4 hours, and a set time of less than 40 minutes.Methods of utilizing and designing compositions for trench patching arealso disclosed.

While the disclosure will be described with respect to preferredembodiment configurations and with respect to particular compositions ormethods used therein, it will be understood that the disclosure is notto be construed as limited in any manner by either such configuration orcomponents described herein. Also, while the particular types ofequipment, compositions and uses are described herein, it will beunderstood that such particular compositions, equipment or uses are notto be construed in a limiting manner. Instead, the functionality ofthose compositions and methods should be appreciated. These and othervariations of the disclosure will become apparent to those skilled inthe art upon a more detailed description of the disclosure.

The advantages and features which characterize the disclosure arepointed out with particularity in the claims annexed hereto and forminga part hereof. For a better understanding of the disclosure, however,reference should be had to the drawing which forms a part hereof and tothe accompanying descriptive matter, in which there is illustrated anddescribed an embodiment of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawing, wherein like numerals represent like partsthroughout the several views.

FIG. 1 illustrates the creation of horizontal cracks by a smallcompactor on a backfilled trench as a function of time.

FIG. 2 illustrates the creation of horizontal cracks by a largecompactor on a backfilled trench as a function of time.

FIG. 3 illustrates the creation of horizontal cracks by the same smallcompactor as FIG. 1 but with a new backfill composition (Mix A) thatdevelops strength faster than the backfill composition used in FIG. 1(Mix B).

FIG. 4 illustrates the creation of horizontal cracks by the same largecompactor as FIG. 2 but with a new backfill composition (Mix A) thatdevelops strength faster than the backfill composition used in FIG. 2(Mix B).

FIG. 5 is a close up view of the horizontal fractures discussed in FIGS.1 through 4.

FIG. 6 illustrates the same horizontal fractures of FIG. 5 aftersaturation with infiltrating water and the first freeze cycle.

FIG. 7 illustrates the horizontal fractures of FIG. 5 after severalcycles of saturation with infiltrating water followed by freeze thawcycles.

FIG. 8 illustrates the hypothetical strength development curves of twodifferent backfill compositions based on both compressive strength (PSI)and the maturity method (degree-hours), as well as the depth offracturing of each mix with the same compactor as function of startingtime.

FIG. 9 illustrates the results of testing different fly ashes atdifferent water to fly ash (W/FA) ratios to determine the resultingfluidity, i.e., spread for each fly ash.

FIG. 10 illustrates the 28 day compressive strengths of variouscementitious fly ashes, e.g., Class C fly ash, as a function of thewater to fly ash ratio (W/FA) with desired fluidity identified by eachcircle.

FIG. 11 illustrates how using the previously tested water demand forseveral fly ashes, including cementitious and non-cementitious flyashes, can help develop the correct ratios and water content for adesired strength.

FIG. 12 illustrates strength versus time curve of compositions from the'422 patent.

FIG. 13 illustrates strength versus time curves of various compositionsfrom the present disclosure in relation to a composition from the '422patent.

FIG. 14 illustrates hypothetical strength versus time curves of variouscompositions from the present disclosure in relation to a compositionfrom the '422 patent.

FIG. 15 illustrates an embodiment of the steps for determining anoptimum composition to meet a specified setting time and removabilitymodulus.

FIG. 16 illustrates an embodiment of the steps for backfilling a voidwith a composition of the present disclosure.

FIG. 17 is an ice lens formation in a composition as suggested by the'422 patent.

FIG. 18 is a pavement patch that has suffered frost heave due to theformation of ice lenses.

FIG. 19 illustrates a strength versus air content graph for an annulargrout composition of an embodiment in the present disclosure.

DETAILED DESCRIPTION

Foamed Backfill Compositions and Methods of Utilizing the Same

The present disclosure provides compositions and methods for reducingfreeze-thaw heave risk over flowable-filled voids; and, moreparticularly, to a composition for reducing horizontal cracks and thesubsequent formation of ice lenses, and methods of producing andutilizing the same.

Generally, one must consider several factors when determining anappropriate composition for backfilling a trench or void in the middleof a public roadway or street. These factors include the flowability orspread of the backfill, the setting time of the backfill, the aircontent of the backfill, the final compressive strength of the backfilland the removability of the backfill.

For example, strength development in backfilling compositions isdirectly related to the amount of cementitious material and watercontent. In an embodiment of this disclosure, the primary cementitiousmaterial is cementitious fly ash. Water content of the composition alsoinfluences strength development as the addition of water controlsflowability or slump. While it is desirable to support the intended use,e.g., traffic loading, the final strength of the composition must stillallow later excavation. In certain embodiments, a composition should beless than 300 psi for ease of later excavation.

In addition, considering the flowability of the compositions will assumethe advantage of the self-compacting and self-leveling qualities ofcomposition. In some embodiments of the present disclosure, theflowability may be determined using ASTM D6103, e.g., utilizing amoistened 3 inch diameter by 6 inch high open-ended cylinder filled witha composition. Along with strength development and flowability, settingtime is an additional factor to consider when determining a suitablecomposition. The faster the composition sets and gains strength afterfilling the void, the sooner the backfilled surface may be paved orpatched and returned to normal use.

The present disclosure reveals a high-performance backfill composition,generating higher early strengths yet still sufficiently low ultimatestrengths, at the same time improving freeze-thaw durability andreducing the occurrence frost-heaved trench patches. In an embodiment,the present disclosure achieves these goals using increased air contentfor a new and improved cementitious fly ash composition for backfillingvoids. In an embodiment, the amount of air content created by varyingfoam additions can be optimized for the strength gain desired, theperformance of specific fly ashes used, and the ambient temperatureduring the backfilling process.

An embodiment of the present invention includes a composition forpreventing ice lens formation comprising between 5% and 60% air; between5% and 90% cementitious fly ash; and between 5% and 70% water, whereinthe composition has a time to set of less than 40 minutes, a compressivestrength of between 10 and 60 PSI after 4 hours and a removabilitymodulus of less than 1.8 after 28 days. In additional embodiments, acomposition of the present disclosure may contain a filler.

The air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. For example, theamount of air within the composition helps control the final strength ofthe backfill. Therefore, a faster set time can be achieved with blendsusing more cementitious fly ash and lower water/fly ash ratios, whilethe ultimate strength can be limited with higher amounts of air content.

In some embodiments, the air content may be determined by the followingformula using wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$In other embodiments, the air content can be determined using ASTM C231.

In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur with prior to addition of water,after addition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and possible filler) with water but prior to applying thecomposition to the void.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. When water penetration is notdesired, a non-pervious cellular foam is preferred. Suitable cellularfoam is available from a variety of sources, e.g., Cellular Concrete,LLC; Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and/or filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content, e.g., the desired finalcompressive strength. In some embodiments, the final air content of thecomposition will be between about 10% and about 75%, between about 11%and about 65%, between about 12% and about 60%, between about 13% andabout 55%, between about 14% and about 50%, between about 15% and about45%, between about 16% and about 40%, between about 17% and about 35%,between about 18% and about 30%, between about 19% and 25%, betweenabout 15% and about 25%, between about 15% and about 30%, or betweenabout 50% and about 70%.

In alternative embodiments, the final air content of the compositionwill be between about 10% and about 30%, between about 11% and about26%, between about 12% and about 22%, between about 13% and about 20%,between about 20% and about 30% or between about 14% and 19%.

In some embodiments, the final air content will be greater than 10%,greater than 12%, greater than 14%, greater than 16%, greater than 18%,greater than 20%, greater than 22%, greater than 24%, greater than 26%,greater than 28%, greater than 30%, greater than 35%, greater than 40%,greater than 50%, or greater than about 60% final air content.

In other embodiments, the final air content of the composition will beless than 40%, less than 35%, less than 30%, less than 28%, less than26%, less than 24%, less, than 22%, less than 20%, less than 18%, lessthan 16%, or less than 14%.

Fly ash can be referred to as either cementitious or pozzolanic. Acementitious material is one that hardens when mixed with water. Apozzolanic material will also harden with water but only afteractivation with an alkaline substance such as lime.

Two major classes of fly ash are specified in ASTM C618 on the basis oftheir chemical composition resulting from the type of coal burned; theseare designated Class F and Class C. Class F is fly ash normally producedfrom burning anthracite or bituminous coal, and Class C is normallyproduced from the burning of subbituminous coal or lignite. Class C flyash usually has cementitious properties in addition to pozzolanicproperties due to free lime, whereas Class F is rarely cementitious whenmixed with water alone.

Some relevant characteristics of fly ash are loss on ignition (LOI),fineness, chemical composition and uniformity. LOI is a measurement ofunburned carbon (coal) remaining in the ash. High carbon levels, thetype of carbon (i.e., activated), the interaction of soluble ions in flyash, and the variability of carbon content are all factors affecting theperformance of fly ashes.

Fineness of fly ash is most closely related to the operating conditionof the coal crushers and the grindability of the coal itself. Finenessis generally defined as the percent by weight of the material retainedon the 0.044 mm (No. 325) sieve. A coarser gradation can result in aless reactive ash and could contain higher carbon contents.

Chemical composition of fly ash relates directly to the mineralchemistry of the parent coal and any additional fuels or additives usedin the combustion or post-combustion processes.

Uniformity of fly ash characteristics from shipment to shipment isanother factor to consider when selecting fly ash or using fly ash. Someguidance documents used for fly ash quality assurance include ACI 229R(Controlled Low Strength Material), ASTM C311 (Sampling and Testing FlyAsh or Natural Pozzulans for Use as Mineral Admixture in Portland CementConcrete), AASHTO M 295 and ASTM C618 (Fly Ash and Raw or CalcinedNatural Pozzolan for Use as a Mineral Admixture in Portland CementConcrete), ASTM C593 (Fly Ash and Other Pozzolans for Use with Lime),ASTM D5239 (Standard Practice for Characterizing Fly Ash for Use in SoilStabilization), and ASTM E1861 (Guide for the Use of Coal Combustionby-products in Structural Fills).

In an embodiment of the present disclosure, the cementitious fly ash isClass C fly ash as defined by ASTM C618 or the standards of a localagency. In other embodiments of the present disclosure, the cementitiousfly ash can have cementitious properties without qualifying as Class Cfly ash under ASTM C618 or an equivalent standard. A cementitious flyash of the present disclosure is a fly ash that sets (e.g., solidifiesto 4 psi) within about thirty minutes at a water content of 30% byweight when water and cementitious fly ash are the only ingredients. Thecementitious fly ash of the present disclosure can be obtained from avariety of sources based on economics, location, chemical properties, oradditional criteria. For example, cementitious fly ash can be obtainedfrom a coal-fired power plant local to the area of eventual use. In someembodiments, the cementitious fly ash is supplemented with additionalcalcium carbonate, free lime or equivalent to provide cementitiousproperties.

In an embodiment of the present disclosure, a composition has betweenabout 5% and about 90% cementitious fly ash, between about 15% and about70% cementitious fly ash, between about 20% and about 60% cementitiousfly ash, between about 20% cementitious fly ash and about 50%cementitious fly ash, between about 35% and about 50% cementitious flyash, and between about 40% and about 47%.

In some embodiments of the present disclosure, a composition has lessthan about 80% cementitious fly ash, less than about 70% cementitiousfly ash, less than about 60% cementitious fly ash, less than about 50%cementitious fly ash, less than about 40% cementitious fly ash, lessthan about 20% cementitious fly ash, or less than about 10% cementitiousfly ash. In additional embodiments of the present disclosure, thecomposition has greater than about 10% cementitious fly ash, greaterthan about 20% cementitious fly ash, cementitious fly ash, greater thanabout 30% cementitious fly ash, greater than about 40% cementitious flyash, greater than about 50% cementitious fly ash, greater than about 60%cementitious fly ash, greater than about 70% cementitious fly ash,greater than about 80% cementitious fly ash, or a greater than about 90%cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. In an embodiment, of the present disclosure, a composition hasa the water content of between about 5% and about 70%, between about 15%and about 60%, between about 25% and about 50%, between about 35% andabout 45%, between about 10% and about 35%, between about 25% and about35%. In additional embodiments, a composition has greater than about 10%water, greater than about 20% water, greater than about 30% water,greater than about 40% water, greater than about 50% water or greaterthan about 60% water. In other embodiments, a composition has less thanabout 55% water, less than about 45% water, less than about 35% water,less than about 24% water, less than about 20% water, less than about15% water, or less than about 10% water. Any water included withadditional ingredients, e.g, aqueous water retarders, foaming agents,etc. under the circumstances encountered in the field by the inventorshas been negligible in comparison to the primary batch water andtherefore has not been included in the above calculations. Depending onthe actual water content of the additional ingredients used it may benecessary to consider the additional water in the final waterconcentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, aggregate, or recycled versionthereof. Determination of the filler material can be based on economics,availability, city, county and/or state specifications, or on thedesired properties of the composition, e.g., desired setting time,flowability, or final compressive strength.

In an embodiment, a composition of the present disclosure will havebetween about 5% and about 80% filler, between about 15% and about 70%filler, between about 25% and about 60% filler, between about 35% andabout 50% filler. In certain embodiments, a composition of the presentdisclosure will have less than about 80% filler, less than about 70%filler, less than about 60% filler, less than about 50% filler, lessthan about 40% filler, less than about 30% filler, less than about 20%filler, or less than about 10% filler. In still other embodiments, acomposition of the present disclosure will have greater than about 10%filler, greater than about 20% filler, greater than about 30% filler,greater than about 40% filler, greater than about 50% filler, greaterthan about 60% filler, or greater than about 70% filler.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. For example, when backfillingtrenches in roadway a quick set time is desired providing the set timeallows sufficient time to complete filling of the void with thecomposition. Despite the desire for a quick set time, the ultimate finalcompressive strength must not exceed the local agency standards, i.e.,maintain good removability modulus numbers. In some embodiments, the settime of the composition is determined by measuring penetrationresistance with a pocket penetrometer (e.g., with a resistance of 4 psias typically used in standard ASTM WK 27337) or cement setting timestandard ASTM C403. In an embodiment of the present disclosure, the settime for a composition can be between about 8 minutes and about 40minutes, between about 9 minutes and about 35 minutes, between about 10minutes and about 30 minutes, between about 11 minutes and about 25minutes, between about 12 minutes and about 20 minutes, or between about13 minutes and about 17 minutes. In additional embodiments, acomposition has a set time of less than 45 minutes, of less than about40 minutes, of less than about 35 minutes, of less than about 30minutes, of less than about 25 minutes, of less than about 20 minutes,of less than about 18 minutes, of less than about 16 minutes, of lessthan about 14 minutes. In other embodiments, a composition has a settime of greater than about 5 minutes, of greater than about 10 minutes,of greater than about 15 minutes, of greater than about 20 minutes, ofgreater than about 25 minutes, or of greater than about 30 minutes.

Compositions of the present disclosure will have a range of compressivestrengths at various times after the addition of a composition to a voiddepending on the desired properties of the composition. For example, andsimilar to set time, a higher earlier compressive strength isadvantageous when working when backfilling trenches in a roadway orother highly traveled area. The higher, earlier compressive strengthallows for the backfilled void to be patched and reopened to use at anearlier time. Again, despite the desire for a high earlier compressivestrength the final compressive strength must not exceed the local agencystandards, i.e., maintain good removability modulus numbers.

In certain embodiments, the compressive strength is measured at 1 hour,2 hours, 4 hours, 1 day, 3 days, 7 days and 28 days where the 28 daymeasurement is considered the final compressive strength. In otherembodiments, the compressive strength is measured more often at smallerintervals. In some embodiments, the compressive strength is measured at90 days. In an embodiment, the compressive strength or bearing capacityor penetration resistance of a composition is measured at 1 hour, 2hours, 4 hours, 7 days, and 28 days after backfilling using ASTM WK27337 or C403.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 1 hour will be between about 3 psi and about 40psi, between about 5 psi and about 35 psi, between about 7 psi and about30 psi. In additional embodiments, the compressive strength of thecomposition at 1 hour will be greater than about 3 psi, will be greaterthan about 5 psi, will be greater than about 10 psi, will be greaterthan about 15 psi, will be greater than about 25 psi, will be greaterthan about 30 psi, or will be greater than about 40 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 1.5 hours will be between about 3 psi and about 40psi, between about 5 psi and about 35 psi, between about 7 psi and about30 psi. In additional embodiments, the compressive strength of thecomposition at 1 hour will be greater than about 3 psi, will be greaterthan about 5 psi, will be greater than about 10 psi, will be greaterthan about 15 psi, will be greater than about 25 psi, will be greaterthan about 30 psi, or will be greater than about 40 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 2 hours will be between about 10 psi and about 40psi, between about 15 psi and about 35 psi, between about 20 psi andabout 30 psi. In additional embodiments, the compressive strength of thecomposition at 2 hours will be greater than about 10 psi, will begreater than about 15 psi, will be greater than about 20 psi, will begreater than about 25 psi, will be greater than about 30 psi, will begreater than about 35 psi, or will be greater than about 40 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 4 hours will be between about 10 psi and about 70psi, 10 psi and about 60 psi, between about 15 psi and about 50 psi,between about 15 psi and about 40 psi, between about 20 psi and about 30psi. In additional embodiments, the compressive strength of thecomposition at 4 hours will be greater than about 10 psi, will begreater than about 15 psi, will be greater than about 20 psi, will begreater than about 25 psi, will be greater than about 30 psi, will begreater than about 35 psi, will be greater than about 40 psi or will begreater than about 50 psi. In an embodiment, the compressive strength ofa composition of the present disclosure at 4 hours will be less thanabout 70 psi, less than about 60 psi, less than about 50 psi, less thanabout 40 psi, less than about 30 psi, or less than about 20 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 28 days hours will be between about 75 psi andabout 300 psi, between about 100 psi and about 250 psi, between about125 psi and about 200 psi. In additional embodiments, the compressivestrength of the composition at 28 days will be greater than about 75psi, will be greater than about 100 psi, will be greater than about 125psi, will be greater than about 150 psi, will be greater than about 175psi, will be greater than about 200 psi, or will be greater than about250 psi. In certain embodiments, the compressive strength of thecomposition at 28 days will be less than about 300 psi, less than about250 psi, less than about 200 psi, less than about 175 psi, less thanabout 150 psi, less than about 125 psi, or less than about 100 psi.

In an embodiment of the present disclosure, an important considerationis the possible re-excavation of the backfilled composition by standardor ordinary excavation equipment. One measure of how easily a previouslybackfilled composition can be removed is the Removability Modulus(“RE”). The Removability Modulus is a commonly used industry standardfor assigning a value to how easily a backfilled composition can beremoved. The lower the RE number the easier the backfilled compositioncan be re-excavated. The Removability Modulus can be determined by thefollowing formula:

${RE} = \frac{W^{1.5} \times 104 \times C^{0.5}}{10^{6}}$W=in-situ unit weight (pcf)C=28 day compressive strength (psi)

In an embodiment of the present disclosure, the RE factor of acomposition is between about 0.3 and between about 3.0, between about0.5 and about 2.5, between about 0.7 and about 2.0, between about 0.8and about 1.8, between about 0.9 and about 1.6, or between about 1.0 andabout 1.4.

In additional embodiments of the present disclosure, the RE factor of acomposition less than about 2.0, less than about 1.8, less than about1.6, less than about 1.5, less than about 1.4, less than about 1.2, lessthan about 1.0, less than about 0.8, or less than about 0.6. In otherembodiments of the present disclosure, the RE factor of a composition isgreater than about 0.3, greater than about 0.6, greater than about 0.9,greater than about 1.1, greater than about 1.3, greater than about 1.5,or greater than about 1.7.

By using certain compositions of the present disclosure, it is possibleto reduce the time from backfilling to paving of the backfilled surface.This reduction in time ultimately reduces the time from backfilling tointended use of the backfilled void, i.e., pedestrian traffic or vehicletraffic. In certain embodiments the backfilled void is suitable forpaving (or equivalent) in less than about 4.0 hours, in less than about3.5 hours, in less than about 3.0 hours, in less than about 2.5 hours,in less than about 2.0 hours, in less than about 1.5 hours, or in lessthan about 1.0 hour.

In certain embodiments of the present disclosure, a suitable compositioncan be defined by the water to fly ash ratio, e.g., when using no filleror when using non-cementitious fly ash filler. In these embodiments, acomposition can have a range of water to fly ash ratios depending on thewater demand of the fly ash, the desired flowability, the desiredsetting time and the desired final compressive strength. In certainembodiments, the water to fly ash ratio of a composition (W/FA) isbetween about 0.2 and about 1.0, between about 0.3 and about 0.8, orbetween about 0.4 and about 0.6. In additional embodiments, the water tofly ash ratio of a composition is greater than about 0.3, greater thanabout 0.5, greater than about 0.7 or greater than about 0.9. In otherembodiments, the water to fly ash ratio is less than about 1.0, lessthan about 0.8, less than about 0.6, less than about 0.5, or less thanabout 0.4.

In certain embodiments of the present disclosure, a composition does notinclude one or more of the following: does not include a water reducer,does not include Portland cement, does not include a set retarder, doesnot include any cementitious material other than cementitious fly ash,does not include a filler, does not include aggregate, does not includegravel, does not include CaCO₃ or lime other than that present in thecementitious fly ash and/or filler, or does not include sand.Furthermore, a composition of the present disclosure does not includenative soils in some embodiments.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611.A slump spread can equal roughly 2.5 times the D6103 spread, both ininches. In certain embodiments of the present disclosure, the slump conespread of a composition is between about 10 and about 45 inches, betweenabout 15 and about 40 inches, is between about 20 inches and about 30inches. In additional embodiments, a composition of the presentdisclosure has a slump cone spread of less than about 50 inches, of lessthan about 40 inches, of less than about 35 inches, of less than about30 inches, or of less than about 25 inches. In certain embodiments, theslump cone spread of a composition is greater than about 20 inches, isgreater than about 25 inches, is greater than about 30 inches, isgreater than about 35 inches, is greater than about 40 inches, or isgreater than about 45 inches.

In additional embodiments, a composition of the present disclosure has aunit weight of between about 20 pcf and about 150 pcf, of between about40 pcf and about 130 pcf, between about 60 pcf and about 100 pcf. Inother embodiments, the unit weight of a composition is greater thanabout 30 pcf, greater than about 50 pcf, greater than about 70 pcf,greater than about 90 pcf, or greater than about 120 pcf. In still otherembodiments, a composition has a unit weight of less than about 130 pcf,of less than about 110 pcf, of less than about 90 pcf, of less thanabout 80 pcf, of less than about 70 pcf, or of less than about 60 pcf.

The present disclosure also provides for a new method of determining acomposition to reduce freeze thaw heave risk. For example, in anembodiment, the present disclosure provides a method for determining asuitable composition for preventing prevent ice lens formationcomprising: determining the water demand of each fly ash within thecomposition; calculating the water demand for a combination of flyashes; determining the compressive strength and densities for acombination of fly ashes; and determining the amount of air contentnecessary for the composition to have a compressive strength of between10 and 60 PSI after 4 hours and a removability modulus of less than 1.8after 28 days. In an additional embodiment, the method may furtherinclude identifying a group of fly ashes for use in the compositionprior to determining the water demand of each fly ash within thecomposition.

In an embodiment, determining the water demand of each fly ash withinthe composition includes determining the water demand of cementitiousfly ashes, specification grade or non-specification grade, as well asnon-cementitious fly ashes, specification grade or non-specificationgrade. In an embodiment, determining the water demand includes addingwater to a fly ash to achieve a spread of between about 6 inches andabout 14 inches using a D6103 spread test. In additional embodiments,determining the water demand includes adding water to a fly ash toachieve a spread of between about 8 inches and about 12 inches or about10 inches using a D6103 spread test. In some embodiments, determiningthe water demand includes plotting different water to fly ash ratios asa function of spread, e.g., as seen in FIG. 9.

Calculating the water demand for a combination of fly ashes can bedetermined in a number of fashions. In an embodiment, the water demandcan be calculated for a combination of ingredients, including fly ashesand additional fillers, i.e., sand. In a specific embodiment, the waterdemand for a specific combination is determined by reference to theindividual water demand of each fly ash or filler. For example, if acementitious fly ash needs a 0.35 water/fly ash ratio to achieve a 10inch spread and a non-cementitious fly ash needs a 0.48 water/fly ashratio to achieve a 10 inch spread, then the total water demand for thecombination of these two ingredients to have between a 8 and 12 inchspread is determined based on the known water demand for each fly ashand the proportion of each fly ash within the composition.

In an embodiment, determining the compressive strength and densities fora combination of fly ashes may include using ASTM C495 and C138 or othercommon tests in the industry. In this disclosure compressive strengthswere measured using ASTM C495. In alternative embodiments, thecompressive strength is determined using other methods apparent to oneof skill in the art. In some embodiments, determining the compressivestrength and densities for a combination of fly ashes includes plottingthe results of compressive strength testing as a function of the waterto fly ash ratio.

Determining the amount of air content necessary to achieve apredetermined compressive strength and removability modulus can includetesting various or the same combination of fly ash and/or filler withvarious air contents to determine the air content necessary to achieve adesired compressive strength and/or removability modulus.

The present disclosure also provides for a novel method of backfilling avoid. For example, in an embodiment, the present disclosure provides amethod of backfilling a void to prevent ice lens formation comprising:mixing cementitious fly ash and filler to a predetermined ratio; addingwater to the mix of cementitious fly ash and filler to make a wetmixture; adding air to the wet mixture, wherein the predetermined mix ofcementitious fly ash and filler, the addition of water and the additionof air makes a composition having a compressive strength of between 10and 60 PSI after 4 hours and a removability modulus of less than 1.8after 28 days; and adding the composition to a void. In an additionalembodiment, the method may include determining that the void is subjectto freezing prior to mixing cementitious fly ash and filler to apredetermined ratio. If the void is not subject to freezing, acomposition of the present disclosure provides an advantageous early settime and early strength while still maintaining a low RE by addition ofair.

Mixing cementitious fly ash and filler to a predetermined ratio caninclude pre-mixing the dry ingredients prior to arriving at theconstruction site or mixing the dry ingredients at the constructionsite. In an embodiment, the composition does not have a filler.

In an embodiment, the addition of water to the mix of cementitious flyash and filler occurs at the construction site. However, in otherembodiments, the water is added prior to arrival at the constructionsite, e.g., in the drum of a ready mix truck. The addition of water mayoccur inside the drum of a volumetric mixing truck or may occur as thedry mix leaves or after the dry mix has left the mixing truck, e.g.,while the dry mix is moving thru a spiral auger.

In some embodiments, the addition of air to the wet mixture can occursimultaneously with the addition of water to the dry ingredients orafter the addition of water to the dry ingredients. In some embodiments,a cellular foam providing the air content is placed directly onto a wetmixture comprising the cementitious fly ash, filler and water. In otherembodiments, the air content is provided by the addition of a drysurfactant to the cementitious fly ash and/or filler prior to additionof water or by using a liquid air entraining admixture during mixing.

In several described embodiments, the completion of the backfillcomposition occurs at the construction site, e.g., by addition of waterand/or air content; however, in other embodiments, the water, aircontent (e.g., cellular foam), cementitious fly ash and/or filler may bepremixed offsite. In this embodiment, a slower set time—thereby allowingtransportation of the premixed composition to the construction site—canbe achieved using a retarding agent. In an embodiment, the retardingagent is citric acid or boric acid (or a combination thereof) while inother embodiments the retarding agent is any agent capable of retardingthe set time of the composition.

The addition of the composition to the void can be achieved usingbuckets, chutes, pumps, conveyors, hoses, augers or any method routinelyused with Portland cement based compositions.

Referring now to the figures, FIG. 1 illustrates the creation ofhorizontal cracks by a small compactor on a backfilled trench as amatter of time and depth. The illustrated trench is roughly 8 ft deepfrom the surface of the backfill 100 to the bottom of the trench 102.The native soil 104 sits under the trench. A small compactor 106 beginsto compact the asphalt trench patch along the surface 100 at differenttimes after the composition (Mix B) is placed in the trench. Withearlier starting times (e.g., 2.0 hours or 4.0 hours), the vibration cancreate horizontal fractures 118 deeper, since the strength of thebackfill near the surface cannot dissipate the vibrations as well (e.g.,to a depth of 5.5 feet if starting at 2.0 hours and depth of 4.0 feet ifstarting at 4.0 hours). As the composition becomes stronger over time,fractures 118 that result from the small compactor 106 are nearer thesurface and do not extend as deep. With a starting time (e.g., 12 hours)that allows sufficient strength in the composition to resist allhorizontal fractures, pavement replacement can safely occur. An attemptto replacement pavement at any time earlier than 12 hours results inhorizontal crack formation, which can ultimately lead to frost heave,due to ice lens development.

FIG. 2 illustrates a larger, heavier, more powerful compactor asdiscussed in FIG. 1. Like FIG. 1, the illustrated trench is roughly 8.0ft deep from the surface of the backfill 100 to the bottom of the trench102. The native soil 104 sits under the trench. A large compactor 108begins to compact the asphalt trench patch along the surface 100 atdifferent times after the composition (Mix B) is placed in the trench.With earlier starting times (e.g., 2 hours or 4 hours), the vibrationcan create horizontal fractures 118 deeper, since the strength of thebackfill near the surface cannot dissipate the vibrations as well (e.g.,to a depth of 8.0 feet if starting at 2 hours and depth of 7.0 feet ifstarting at 4 hours). As the composition becomes stronger over time,fractures 118 that result from the large compactor 108 are nearer thesurface and do not extend as deep. With a starting time (e.g., greaterthan 14 hours) that allows sufficient strength in the composition toresist all horizontal fractures, pavement replacement can safely occur.An attempt to replace pavement at 14 hours or earlier in thishypothetical example results in horizontal crack formation, which canultimately lead to frost heave. In this figure, with the same mix asFIG. 2, fractures are generated deeper with any given start time with alarger compactor.

FIG. 3 illustrates the previously depicted small compactor 106 of FIG. 1and the same conditions as FIG. 1 but uses a different composition,i.e., Mix A, to fill the trench. Mix A sets up and hardens faster thanthe Mix B used in FIG. 1 and FIG. 2. At a faster setting time due to afaster setting composition, the small compactor 106 will induceshallower horizontal fracture at any given start time, e.g., 3.0 feet at2 hours and 2 feet at 4 hours. With a faster setting Mix A, the safestarting time has been reduced from 12-hours (e.g., FIG. 1) to 8-hoursusing hypothetical Mix A over Mix B.

FIG. 4 illustrates the previously depicted large compactor 108 of FIG. 2and the same conditions as FIG. 2 but uses a different composition,i.e., Mix A, to fill the trench. Mix A sets up and hardens faster thanthe Mix B used in FIG. 1 and FIG. 2. At a faster setting time due to afaster setting composition, the large compactor 108 will induceshallower horizontal fracture at any given start time, e.g., 5.0 feet at2 hours and 4.0 feet at 4 hours. With a faster setting Mix A, the safestarting time has been reduced from greater than 14 hours (e.g., FIG. 2)to 14 hours using hypothetical Mix A over Mix B.

FIG. 5 illustrates a backfilled trench 120 that has been paved 116 tomatch the surrounding surface pavement 114. However, the paving occurredtoo soon and induced horizontal fractures 118 to the bottom of thetrench 102 or to a depth above the bottom of the trench 103, both aboveand below the frost line 112. The previously described horizontalfractures 118 (e.g., FIGS. 1-4) are a result of paving occurring at atime from backfill when the backfill composition had insufficientstrength to resist horizontal shear forces. These fractures 118 canoccur below the local depth of frost penetration 112 in a severe winter,depending on the mixture and the compaction time/equipment.

FIG. 6 illustrates a backfilled trench 120 of FIG. 5 following a freezecycle. The horizontal fractures 118 of FIG. 5 had become saturated withinfiltrating water—from the surface and/or ground water (e.g., 122)—andexpanded after the first freezing cycle to become larger fractures 124.The 11% expansion of water from freezing has enlarged the horizontalfractures 124 above the depth of frost penetration. The resultingenlargement/expansion of the horizontal fractures 124 has caused frostheave, pushing the original backfilled trench pavement 116 above thesurrounding surface pavement 114.

FIG. 7 illustrates a backfilled trench 120 of FIGS. 5 & 6 followingseveral freeze thaw cycles. The horizontal fractures 118 of FIG. 5 havebecome saturated with infiltrating water (e.g., 122) and expanded aftermultiple freezing cycles to become larger fractures 126. The 11%expansion of water from freezing has enlarged the horizontal fractures126 above the depth of frost penetration. The resultingenlargement/expansion of the horizontal fractures 126 has worsened thefrost heave of FIG. 6, pushing the original backfilled trench pavement116 even farther above the surrounding surface pavement 114. The heightof heave of the pavement patch (e.g., height between 116 and 114) isapproximately equal to the sum of the thicknesses of all ice lensesformed in the compaction fractures below 126.

FIG. 8 illustrates strength development curves for two differenthypothetical compositions (e.g., Mix 1 and Mix 2) without airentrainment, based on both compressive strength (psi), the maturitymethod (degree-hours), as well as the depth of fracturing of these twomixtures with a compactor (same for both) as a function of startingtime. Mild compaction problems 124 (e.g., fractures are shallow and lessthan 1 foot), moderate compaction problems 126 (e.g., fractures extendto a depth of 3 feet) and severe compaction problems 128 (e.g., fractureextend to a depth of 5 feet) are determined by looking plotting thedepth of horizontal fractures as a function of time. Even mildcompaction problems can result ice lens formation and frost heave.

Still generally referring to FIG. 8, in an embodiment, the first step inreducing freeze-thaw heave risk with backfilled trenches is to conductan on-site test with a given compactor and a given composition. In time,various size ranges of compactors can be tested and in an embodiment ofthe present disclosure quantified into groups, e.g., small, medium andlarge, based on test results and manufacturer's output ratings ofcompactive energy. Similarly, in an embodiment of the presentdisclosure, compositions can be qualified, e.g., slow, medium, fast andextra fast, based on the time to achieve a specified strength level,i.e., 4-hour/200 psi mix. Such equipment and mix categories canfacilitate proper ordering and placement of the correct composition,while successfully reducing freeze-thaw heave risk.

For example, a suitably-sized test trench is excavated and filled with acomposition of the present disclosure, as indicated by Mix 1 in FIG. 8.Maturity probes are inserted at various depths in the composition andactivated at the time of placement. At various times along the length ofthe backfilled trench, the compactor is operated for a suitable numberof passes to properly compact asphalt. The next day, coring is performedto determine the depth of compaction fractures associated with thedifferent starting times. These fracture depths vs. starting-times areplotted on a graph, as shown in FIG. 8. Typically, the safe startingtime for any given compactor & mixture combination would be the firsttime that no compaction fractures can occur. However, pavement patchmaterials could be compacted if the depth of the patch materials exceedsthe local frost depth; any compaction fractures below the final frostdepth would not contribute to deleterious heaving.

Still referring to FIG. 8, based on previously performed laboratorytesting of Mix 1, the strength development versus time curve can begraphed as show in FIG. 8, both in terms of compressive strength (psi),and Maturity Values (degree-hours) recorded in a test cylinder. Withthis correlation data, the compositions' actual strength (150 psi) inthe trench experiment can be properly estimated, based on the maturityprobes in the trench fill (400 degree-hours) and using the correlationgraph. While the maturity values from test cylinders at a given timewill not match the trench values at the same time, (due toheat-generation of mass-effects of samples), the trench values can beused on the graph to determine the time/strength mixture needed. Thus,strength required to resist compaction fractures can readily bedetermined to specify mixture performance vs. a desired starting time.

Still referring to FIG. 8, the hypothetical required compressivestrength was determined to be 150 psi, and the safe starting time forMix 1 was 13 hours. If this was too long to repair the trench and openthe street to traffic, a faster mix could be selected. Based on asimilar strength-development curve for Mix 2, 150 psi should be achieved(under laboratory conditions) within 3.75 hours, although at a differentMaturity value (600 degree-hours) than Mix 1 exhibited at 150 psi.Hence, a safe starting time for compaction would be field—verified whenthe maturity probes in the trench filled with Mix 2 achieve the requireddegree-hour value corresponding to 150 psi for Mix 2 (600 degree-hours).

FIG. 9 illustrates graphically the results of testing different flyashes at different W/FA ratios to determine the resulting fluidity usingASTM D6103. The following cementitious fly ashes were tested: Gentleman136, California 140, and Arapahoe 144. In addition, Valmont Class F flyash 142 was tested. In this case, the spread was determined by liftingan open-ended 3 inch diameter by 6 inch tall cylinder mold (ASTM D6103).This size is convenient for smaller laboratory batches and can bereasonably correlated to using a 12 inch high concrete slump cone astypical for self-consolidating concrete mixtures. As shown in the graph,different fly ashes have different “water demand” curves (e.g., 136,140, 142, and 144), to achieve a desired fluidity; in this case, a 10″spread 132 is desired, with maximum spread of 12 inches 134 and aminimum spread of 8 inches 130. The graphs can be used to estimate theW/FA ratio at the exact spread desired. For example, the desired W/FAratio for a 10 inch spread of California Class C ash 136 is roughly 0.26as indicated by the intersection point 138 of the California Class C ashgraph 136 with the 10 inch spread line 132. The same determination ispossible for the other graphed fly ashes, e.g., 138, 148 and 146.

FIG. 10 illustrates typical 4-hour compressive strengths of variouscementitious fly ashes as a function of their W/FA ratios. Afterstrength testing has occurred, the estimated strength at the W/FA ratioassociated with their desired 10 inch spread can be estimated from thechart. For example, at a 10 inch spread, Arapahoe 151 has a strength of125 psi as indicated by the circle at 153. For example, at a 10 inchspread, California 152 has a strength of 200 psi as indicated by thecircle at 155. For example, at a 10 inch spread, Gentlemen 150 has astrength of 320 psi as indicated by the circle at 157.

FIG. 11 illustrates how testing the water demand of each fly ash(cementitious or non-cementitious) separately can be useful indetermining the estimated 4-hour strength of various blends of Class C &F fly ashes. In this case, depending on the blend, the W/FA ratio of theblend is first mathematically estimated. Since the non-cementitious flyash does not influence early strengths, the estimated blended W/FA canbe used with the strength-W/FA curve for the cementitious fly ash toestimate the blended strength. For example, a 50-50% blend of Gentlemanand Valmont is estimated with a W/FA ratio of 0.39, resulting in 120 psiat 4-hours.

FIG. 12 illustrates the strength vs. time curve taught by the '422patent 166. One way to reach higher early strengths would be to usehigher cementitious fly ash blends and/or lower water contents; howeverthese would result in ultimate strengths greater than desired or allowedby ACI 229. For example, a 1:1 Gentleman to Valmont blend 164 results inearlier higher strengths but ultimately results in a final strengthabove that recommended by ACI 229, represented by 160.

FIG. 13 illustrates strength curves at varying air contents, created byadding increasing amounts of cellular foam to compositions of thepresent disclosure. For example, a composition of the '422 patent withno cellular foam 176, a composition of the present disclosure entrainedwith cellular foam resulting in 14% air 172, a composition of thepresent disclosure with no air 170, a composition of the presentdisclosure entrained with cellular foam resulting in 28% air 174, acomposition of the present disclosure entrained with cellular foamresulting in 33% air 177, a composition of the present disclosureentrained with cellular foam resulting in 41% air 178 and a compositionof the present disclosure entrained with cellular foam resulting in 54%air 179.

Still referring to FIG. 13, the optimization process will includebalancing higher early strengths and acceptable ultimate strengths. Inthis case, a moderately-reacting cementitious fly ash (Arapahoe) wasused without air entrainment or with varying degrees of air entrainment,mimicking the early strengths of the '422 non-air formulation 176. Inalternative embodiments, more reactive fly ashes (such as Gentleman) canbe used to achieve faster-setting times and higher-early strengths, butstill effectively limited ultimate strengths with sufficiently high aircontents.

Laboratory and field testing has shown that the setting time iscomparable with various air contents; however the initial earlystrengths are affected by higher air contents, which can impact earlyplacement of street repair patches.

TABLE 1 Arapahoe-Valmont 50-50 Mixes, varying air content % 4 1- 7- 28-FIG. UW Air Hour day day day RE 13 No. 101 0 56 88 142 200 1.50 170 8714 56 125 155 182 1.14 172 73 28 38 54 81 136 0.75 174 68 33 25 48 75 700.49 177 60 41 <20 (14) 33 36 41 0.31 178 46 54 <20 (9)  <20 (16) 24 260.17 179

As shown in the table above, the RE of foamed compositions decreaseswith increased air-contents, both because of lower unit weights andlowered compressive strengths. Field trials with compositions foamed tovarious air contents, then later excavated with a tractor backhoeconfirmed the relative ease of removing hardened compositions withhigher air.

FIG. 14 illustrates a hypothetical graph, in an embodiment,demonstrating the compressive strength as a function of time forcompositions with varying air content. For example, a composition of the'422 patent with no cellular foam 188, a composition of the presentdisclosure with no air 180, a composition of the present disclosure withlow air content 182, a composition of the present disclosure with mediumair content 184, a composition of the present disclosure with high foamcontent 186 and a composition of the present disclosure with too muchair content 190. The ACI 229 strength limit is represented by 160.

FIG. 15 illustrates an embodiment of a method 200 of the presentdisclosure. To increase the field performance and lab predictability oftest results, a better mix design & testing protocol was needed. At step202, fly ashes of interest are tested separately for consistency versuswater demand. Test results of slump-cone and/or 3×6 cylinder spreads(inches) will be graphed at varied water contents somewhat above, at,and somewhat below the desired consistency of the composition (e.g. FIG.9). A curve can be fit through the measured data points, and a specificwater demand can be determined at the desired consistency (e.g., a 26inch cone-spread or 10 inch cylinder spread). In addition, at step 202,the water demand for a filler other than non-cementitious fly ash can bedetermined. At step 204, the estimated water demand of a composition,i.e., 30% cementitious fly ash and 30% non-cementitious fly ash, isdetermined by proportioning of the separate water demands determined instep 202.

At step 206, the compressive strengths and densities of a composition isdetermined. Compressive strength versus time testing is performed onvarious compositions, e.g., same composition with different water/flyash ratios, to determine the compressive strengths at different watercontents. These tests can range from a composition with using onlycementitious fly ash at the desired consistency to a composition withthe highest water demand estimated for the blend of cementitious fly ashand non-cementitious fly ash or filler). Since the final resultingcompressive strength of the blended fly ash mixture is dependent on theactual water/fly ash ratio acting on the cementitious material,compressive strengths of any suggested blend can be estimated todetermine if further verification testing of the blend is warranted.

At step 210, the amount air content needed for composition from step 206to have a desired RE is determined. For example, a composition from step206 may set in the desired time, e.g., 30 minutes, but may have a highfinal compressive strength resulting in a high RE. Thus, the amount ofair content, e.g., cellular foam, necessary to reduce the finalcompressive strength is determined. In some embodiments, the finalcompressive strength and unit weight is retested after determining thefinal air content.

The time of initial set is determined when the weight of the pocketpenetrometer (approximately 0.2 lb) was supported by the surface of thecomposition on a diameter of 0.25 inch; this represents a penetrationpressure of approximately 4.0 psi. Further values are measured bypushing the penetrometer into the fly ash mixture.

FIG. 16 illustrates an embodiment of a method 220 presently disclosed.At step 222, the dry ingredients are combined to a desired ratio. In anembodiment, the dry ingredients comprise cementitious fly ash andnon-cementitious fly ash. In additional embodiments, the dry ingredientscomprise cementitious fly ash, non-cementitious fly ash and additionalfillers, e.g., sand. In some embodiments, the dry ingredients are onlycementitious fly ash. In other embodiments, the dry ingredients do notcontain non-cementitious fly ash. In an embodiment, step 222 occursoffsite, i.e., not at the construction site.

At step 224, water is added to the dry ingredients. At step 226, air isadded to the wet mixture, e.g., cellular foam is added to the wetmixture. At step 228, the wet mixture with air content is added to thedesired void resulting in a backfill composition stronger than nativesoils and structural fills but not harder to excavate.

FIG. 17 is a picture of ice lens formation in a composition of the '422patent. A 3.75 inch diameter core 230 was taken from backfill using acomposition as taught by the '422 patent. The larger, lower ice lens 232is 0.40 inches thick. The ice lenses 232 formed by the subsequentfiltration of water into the horizontal cracks in the backfillcomposition combined with multiple freeze thaw cycles. In FIG. 17,multiple ice lenses of varying thicknesses have formed in the horizontalcracks of the backfill.

FIG. 18 is a picture of a road surface patch 242 over a backfillcomposition as taught by the '422 patent. As is evident from thepicture, ice lens formation has caused frost heave 244 and the patch 242rising above the surrounding pavement 248. A blackberry cellular phone246 provides reference.

Annular Grout Compositions and Methods of Utilizing the Same

The present disclosure also provides compositions and methods forfilling surface and subsurface voids with cellular, annular groutAnnular grout is historically a Portland cement composition for use infilling subterranean voids, i.e., areas around an underground pipe.Typically, access to the void is restricted, such that, the compositionfor filling the void must be pumped into the void without direct accessto the entire void. For example, annular grout is typically used whenreplacing an older underground pipe with a new pipe by slip lining theold pipe with a new pipe. Following insertion of a new pipe into the oldpipe, the void between the exterior wall of the new pipe and theinterior wall of the old pipe is filled with an annular groutcomposition. In another example, annular grout is used to fill asubterranean void that either naturally occurred or was left fromconstruction or depletion of well or mine. The annular grout is pumpedinto the subterranean void through an access port on the surface. Incertain embodiments, annular grout is used fill the void left by removalof an underground pipe or to fill the old pipe itself. Annular grout canalso be used to fill underground fuel tanks or backfill behind walls,buildings, or as embankment materials.

Compositions for use as an annular grout must have sufficient fluidityfor pumping and subsequently filling voids without requiring anycompaction. Compositions for use as annular grout must also have adelayed set time to allow the grout to flow the length or width of thevoid without setting. Compositions of the present disclosure exhibitsufficient fluidity for pumping, set-times for extended durations ofinstallation, yet sufficiently high strengths at the required lowdensities.

For example, when filling the void left between a new pipe and old pipeby slip lining an old pipe, the composition of annular grout mustmaintain sufficient fluidity to travel the length of the pipe beforesetting. In some embodiments, sufficient density is necessary todisplace ground water in the void.

In an embodiment of the present disclosure, a low density annular groutcomposition for filling voids comprises between 30%-85% air by volume;between 50% -90% cementitious fly ash by weight; between 10% and 45%water by weight; and between 0.01% and 2% set retarder by weight,wherein the composition has compressive strength of between 100 and 600psi at seven days, a compressive strength of less than 1500 psi at 28days, and a density of between 25 and 75 pcf.

The air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. For example, theamount of air within the composition helps control the final density andstrength of the annular grout. A lower ultimate strength can be limitedwith higher amounts of air content.

In some embodiments, the air content may be determined by the followingformula using wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$In other embodiments, the air content can be determined using ASTM C231.

In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur prior to addition of water, afteraddition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and possible filler) with water but prior to applying thecomposition to the void.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. Suitable cellular foam isavailable from a variety of sources, e.g., Cellular Concrete, LLC;Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and/or filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content, e.g., the desired finalcompressive strength. In some embodiments, the final air content of thecomposition will be between about 35% and about 85%, between about 40%and about 80%, between about 45% and about 75%, between about 50% andabout 70%, between about 50% and about 65%, between about 50% and about75%, between about 35% and about 50%, between about 35% and about 60%,between about 50% and about 80%, between about 60% and 80%, betweenabout 40% and about 50%, between about 40% and about 60%, or betweenabout 35% and about 55%.

In some embodiments, the final air content will be greater than 20%,greater than 25%, greater than 30%, greater than 35%, greater than 40%,greater than 45%, greater than 50%, greater than 55%, greater than 60%,greater than 65%, greater than 70%, greater than 75%.

In other embodiments, the final air content of the composition will beless than 80%, less than 75%, less than 70%, less than 65%, less than60%, less than 55%, less than 50%, less than 45%, less than 40%, lessthan 35%, or less than 30%.

In an embodiment of the present disclosure, the cementitious fly ash isClass C fly ash as defined by ASTM C618 or the standards of a localagency. In other embodiments of the present disclosure, the cementitiousfly ash can have cementitious properties without qualifying as Class Cfly ash under ASTM C618 or an equivalent standard. A cementitious flyash of the present disclosure is a fly ash that sets (e.g., solidifiesto 4 psi) within about thirty minutes at a water content of 30% byweight when water and cementitious fly ash are the only ingredients.

In an embodiment of the present disclosure, a composition has betweenabout 50% and about 90% cementitious fly ash, between about 55% andabout 85% cementitious fly ash, between about 60% and about 80%cementitious fly ash, between about 65% cementitious fly ash and about75% cementitious fly ash, between about 50% and about 70% cementitiousfly ash, and between about 50% and about 60% cementitious fly ash.

In some embodiments of the present disclosure, a composition has lessthan about 90% cementitious fly ash, less than about 85% cementitiousfly ash, less than about 80% cementitious fly ash, less than about 75%cementitious fly ash, less than about 70% cementitious fly ash, lessthan about 65% cementitious fly ash, less than about 60% cementitiousfly ash or less than about 55% cementitious fly ash. In additionalembodiments of the present disclosure, the composition has greater thanabout 50% cementitious fly ash, greater than about 55% cementitious flyash, cementitious fly ash, greater than about 60% cementitious fly ash,greater than about 65% cementitious fly ash, greater than about 70%cementitious fly ash, greater than about 75% cementitious fly ash,greater than about 80% cementitious fly ash, or greater than about 85%cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. It is advantageous for the flowability of an annular groutcomposition to allow efficient pumping and be capable of traveling thedistance of the void, e.g., pipe. In an embodiment of the presentdisclosure, a composition has a the water content of between about 10%and about 45%, between about 15% and about 35%, between about 20% andabout 30%, between about 10% and about 30%, between about 10% and about25%, between about 20% and about 45%. In additional embodiments, acomposition has greater than about 10% water, greater than about 20%water, greater than about 30% water, greater than about 40% water, orgreater than about 50% water. In other embodiments, a composition hasless than about 55% water, less than about 45% water, less than about35% water, less than about 25% water, less than about 20% water, lessthan about 15% water, or less than about 10% water. Any water includedwith additional ingredients, e.g., aqueous water retarders, foamingagents, etc. under the circumstances encountered in the field by theinventors has been negligible in comparison to the primary batch waterand therefore has not been included in the above calculations. Dependingon the actual water content of the additional ingredients used it may benecessary to consider the additional water in the final waterconcentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., Type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, aggregate, or recycled versionthereof. Determination of the filler material can be based on economics,availability, city, county and/or state specifications, or on thedesired properties of the composition, e.g., desired setting time,flowability, or final compressive strength.

In an embodiment, a composition of the present disclosure will havebetween about 1% and about 40% filler, between about 5% and about 35%filler, between about 10% and about 30% filler, between about 15% andabout 25% filler, between about 1% and about 20%, between about 5% andabout 20%, between about 5% and about 15%, between about 30% and about40%. In certain embodiments, a composition of the present disclosurewill have less than about 50% filler, less than about 70% filler, lessthan about 60% filler, less than about 50% filler, less than about 40%filler, less than about 35% filler, less than about 30% filler, lessthan about 25% filler, less than about 20% filler, less than about 15%filler, less than about 10% filler, less than about 5% filler or lessthan about 3% filler. In still other embodiments, a composition of thepresent disclosure will have greater than about 10% filler, greater thanabout 15% filler, greater than about 20% filler, greater than about 25%filler, greater than about 30% filler, greater than about 35% filler, orgreater than about 40% filler.

Annular grout compositions will comprise a set retarder in someembodiments. A set retarder is a compound capable of delaying the settime of the composition. In certain embodiments, delaying the set timeis necessary to allow an annular grout to completely fill a void beforesetting, e.g., to travel the length of a pipe from composition insertionpoint to a determined end point. An example of a set retarder may becitric acid or borax, or a combination thereof. In certain embodiments,the set retarder is liquid while in other embodiments the set retarderis a powder. An appropriate set retarder will be well known to a personof ordinary skill in the art.

In an embodiment, the concentration of set retarder is between about0.01% and about 3%, between about 0.01% and about 2% between about 0.05%and about 2.5%, between about 0.1% and about 2%, between about 0.5% andabout 1.5%, between about 0.0001% and about 1.0%. In some embodiments,the set retarder is greater than about 0.001%, is greater than about0.01% is greater than about 0.05%, is greater than about 0.1%, isgreater than about 0.5%, is greater than about 1.0%, is greater thanabout 1.5%, or is greater than about 2.0%. In certain embodiments, theset retarder is less than about 3.0%, less than about 2.5%, less thanabout 2.0%, less than about 1.5%, less than about 1.0%, less than about0.5%, less than about 0.3%, less than about 0.1%, less than about 0.01%,less than about 0.001%.

In some embodiments, the composition may further comprise a waterreducer. Water reducers may be used when a higher final strength isdesired at a specified density and fluidity. In some embodiments thewater reducer will be powder while in other embodiments it will be aliquid water reducer. In an embodiment, the water reducer is CHRYSO 256(high range) or 380 (midrange) or similar composition suitable for usein the disclosed composition. A water reducer is a chemical (e.g.,chemical composition) that allows a mixture to maintain the samefluidity with less water or more fluidity with the same amount of water.

In an embodiment, the concentration of the water reducer is betweenabout 0.01% and about 3%, between about 0.01% and about 2% between about0.05% and about 2.5%, between about 0.1% and about 2%, between about0.5% and about 1.5%, between about 0.0001% and about 1.0%. In someembodiments, the water reducer is greater than about 0.001%, is greaterthan about 0.01% is greater than about 0.05%, is greater than about0.1%, is greater than about 0.5%, is greater than about 1.0%, is greaterthan about 1.5%, or is greater than about 2.0%. In certain embodiments,the water reducer is less than about 3.0%, less than about 2.5%, lessthan about 2.0%, less than about 1.5%, less than about 1.0%, less thanabout 0.5%, less than about 0.3%, less than about 0.1%, less than about0.01%, less than about 0.001%.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. For example, the longer the pipeor the slower the pump rate, the longer the set time necessary tocomplete filling the pipe before the composition sets. In someembodiments, the set time of the composition is determined by measuringpenetration resistance with a pocket penetrometer (e.g., with a staticresistance of 4 psi as used in standard ASTM WK 27337) or cement settingtime standard ASTM C403. In an embodiment of the present disclosure, theset time for a composition can be between about 60 minutes and about 8hours, between about 2 hours and about 7 hours, between about 3 hoursand about 6 hours. In additional embodiments, a composition has a settime of less than 10 hours, of less than about 9 hours, of less thanabout 8 hours, of less than about 7 hours, of less than about 6 hours,of less than about 5 hours, of less than about 4 hours, of less thanabout 3 hours, of less than about 2 hours or of less than about 1 hour.In other embodiments, a composition has a set time of greater than about2 hours, of greater than about 3 hours, of greater than about 4 hours,of greater than about 5 hours, of greater than about 6 hours, of greaterthan about 7 hours, of greater than about 8 hours, or of greater thanabout 9 hours.

Compositions of the present disclosure will have a range of compressivestrengths at various times after the addition of a composition to a voiddepending on the desired properties of the composition.

In certain embodiments, the compressive strength is measured at 1 day, 3days, 7 days and 28 days where the 28 day measurement is considered thefinal compressive strength. In other embodiments, the compressivestrength is measured more often at smaller intervals or less often atlarger intervals. In some embodiments, the compressive strength ismeasured at 90 days. In an embodiment, the bearing penetration orcapacity resistance of a composition is measured at 1 day, 3 days, 7days and 28 days using ASTM WK 27337 or C403.

In an embodiment, the compressive strength (e.g., tested by ASTM C495)of a composition of the present disclosure at seven days will be betweenabout 100 psi and about 600 psi, 150 psi and about 550 psi, betweenabout 200 psi and about 500 psi, between about 250 psi and about 450psi, between about 100 psi and about 500 psi, between about 100 psi andabout 400 psi, between about 100 psi and about 300 psi, between about300 psi and about 600 psi. In additional embodiments, the compressivestrength of the composition at seven days will be greater than about 100psi, will be greater than about 150 psi, will be greater than about 200psi, will be greater than about 250 psi, will be greater than about 300psi, will be greater than about 350 psi, will be greater than about 400psi or will be greater than about 500 psi. In an embodiment, thecompressive strength of a composition of the present disclosure at sevendays will be less than about 600 psi, less than about 500 psi, less thanabout 450 psi, less than about 400 psi, less than about 350 psi, lessthan about 300 psi, less than about 250 psi, or less than about 200 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 28 days will be between about 200 psi and about500 psi, between about 200 psi and about 600 psi, between about 200 psiand about 1500 psi, between about 300 psi and about 1300 psi, betweenabout 300 psi and about 1100 psi, between about 300 psi and about 900psi, between about 300 psi and about 700 psi. In additional embodiments,the compressive strength of the composition at 28 days will be greaterthan about 200 psi, will be greater than about 300 psi, will be greaterthan about 400 psi, will be greater than about 500 psi, will be greaterthan about 600 psi, will be greater than about 700 psi, or will begreater than about 800 psi. In certain embodiments, the compressivestrength of the composition at 28 days will be less than about 1500 psi,less than about 1250 psi, less than about 1000 psi, less than about 800psi, less than about 700 psi, less than about 600 psi, or less thanabout 500 psi.

In certain embodiments of the present disclosure, a suitable compositioncan be defined by the water to fly ash ratio, e.g., when using nofiller, when using non-cementitious fly ash filler, or other suitablefiller like sand. The water to fly ash ratio will be a water tocementitious fly ash plus additional non-cementitious fly ash fillerratio.

In certain embodiments, a composition can have a range of water to flyash ratios depending on the water demand of the fly ash (or includedfiller), the desired flowability, the desired setting time and thedesired final compressive strength. In certain embodiments, the water tofly ash ratio of a composition (W/FA) is between about 0.15 and about0.25, between about 0.2 and about 0.6, between about 0.2 and about 0.5,between about 0.2 and about 0.4 or between about 0.25 and about 0.35. Inadditional embodiments, the water to fly ash ratio of a composition isgreater than about 0.2, greater than about 0.25, greater than about 0.3,greater than about 0.35 or greater than about 0.4. In other embodiments,the water to fly ash ratio is less than about 0.6, less than about 0.5,less than about 0.4, less than about 0.35, less than about 0.3, lessthan about 0.25 or less than about 0.2.

In certain embodiments of the present disclosure, an annular groutcomposition does not include one or more of the following: does notinclude a water reducer, does not include Portland cement, does notinclude a set retarder, does not include any cementitious material otherthan cementitious fly ash, does not include a filler, does not includeaggregate, does not include gravel, does not include CaCO₃ or lime otherthan that present in the cementitious fly ash and/or filler, or does notinclude sand. Furthermore, a composition of the present disclosure doesnot include native soils in some embodiments.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611or spread as determined by D6103.

The density in an annular grout composition is important in certainembodiments. For example, when filling the void left between pipes in aslip-lined pipe, the density is often limited to a specified maximumdensity to prevent or limit the composition from floating the pipe beinggrouted (e.g., preventing the new internal pipe from floating on top ofthe composition thereby causing the top surface of the internal pipe tocontact the top surface side of the old external pipe). In other cases,the density greater is than water to displace residual water in thevoid.

In embodiments, a composition of the present disclosure has a unitweight of between about 25 pcf and about 75 pcf, of between about 30 pcfand about 70 pcf, between about 35 pcf and about 65 pcf, between about40 pcf and about 60 pcf, between about 45 pcf and about 55 pcf, betweenabout 25 and 55 pcf, between about 35 and 55 pcf, between about 45 pcfand 65 pcf or between about 45 pcf and 60 pcf. In other embodiments, theunit weight of a composition is greater than about 30 pcf, greater thanabout 35 pcf, greater than about 40 pcf, greater than about 45 pcf,greater than about 50 pcf, greater than about 55 pcf, or greater thanabout 60 pcf. In still other embodiments, a composition has a unitweight of less than about 70 pcf, of less than about 65 pcf, of lessthan about 60 pcf, of less than about 55 pcf, of less than about 50 pcf,of less than about 45 pcf, of less than about 40 pcf or of less thanabout 35 pcf.

The present disclosure also contemplates a method of determining a lowdensity annular grout composition for filling a subterranean voidcomprising: identifying at least one fly ash for use in the composition;determining a water demand of each fly ash within the composition;calculating a water demand for the composition; determining acompressive strength for the composition; determining the amount of aircontent necessary for the composition to have a compressive strength ofbetween 200 and 600 psi at seven days, a compressive strength of lessthan 1500 psi at 28 days, and a density of between 25 and 75 pcf;determining the time necessary to fill the void; and determining theconcentration of set retarder necessary to delay the composition fromsetting in less time than necessary to fill the void.

The determination of suitable fly ash, water demand, compressivestrength, air content, density can be accomplished as discussedelsewhere in this application. Determining the time necessary to fillany given void will can be a function of the length of the void, thevolume of the void, the flowability of the composition, and the pumprate of the composition. Additional factors can include the timenecessary to mix an additional volume of composition or to switch mixingtrucks, or cleaning pumps and hoses after pumping the composition intothe void. Determining the concentration of set retarder necessary todelay the composition from setting too soon can include accounting forthe retarder type, the final density of the composition, thecementitious fly ash content, the water to cementitious fly ash ratio orany other factor influencing the activity of the set retarder.

The present disclosure also contemplates a method of filling a void witha low density annular grout composition comprising: determining the timenecessary to fill the void; adding water and set retarder to acementitious fly ash to make a wet mixture; adding air to the wetmixture, wherein the composition has a compressive strength of between100 and 600 psi at seven days, a compressive strength of less than 1500psi at 28 days, and a density of between 20 and 75 pcf; and adding thecomposition to the void.

Referring now to FIG. 19 which represents the compressive strengthtesting versus air content for a composition having a 0.25 water to flyash ratio. The compressive strength versus air content is shown at oneday 304, at seven days 302, and at twenty eight days 300.

One of the challenges to designing these compositions is achieving thedesired minimum compressive strength, at the desired density, given theamount of time required to test for strength and the numerouscombinations of two fly ashes, at different water contents, and theability of a water reducer to increase strength. A mix design aid hasbeen developed to expedite the process of determining a suitablecombination of materials.

With a given cementitious fly ash, first mix it at a water to fly ashratio of 0.25, which typically gives sufficient fluidity to mix varyingamounts of cellular foam into. This is considered the baseline slurrymixtures (e.g., FIG. 19). Next determine the fluid density at the timeof mixing, then fabricate penetration resistance and compressivestrength specimens to test at varying ages; typically 4 hours, 24 hours,3 days, 7 days, and 28 days.

With this baseline slurry mixture, add increasing amounts of foam toachieve various air contents; approximately 10%, 20%, 30%, 40%, 50%,60%, 70% and 80% would be suggested, however 20%, 40%, 60% and 80% couldbe used to expedite the process. Once penetration resistance andcompressive testing is complete for each of these foamed mixtures, thetest results can be plotted on a psi versus air content graph for eachage of testing, e.g., FIG. 19.

Next different slurry combinations can be tested for strength &penetration resistance at the corresponding ages, but without adding anycellular foam. For higher strengths at a given density, a water-reducerwould be used at different dosages to maintain fluidity for mixing foamand pumping, yet achieve lower water to fly ash ratios for those higherstrengths. Conversely, if less strength is needed than given by thebaseline mixture at varying air contents & densities, higher W/FA ratiosand/or varying amounts of filler (fly ash) can be used for improvedeconomy of the desired mixture. Next, determine the fluid density ofeach additional non-foamed slurry, and fabricate strength specimens asdescribed in the proceeding sections.

In an embodiment, since the inherent strength of any given compositionis a function of the base slurry strength and the amount of air content,this mix design aid can be used to estimate results from a given set ofproportions by following the following protocol.

First, for a given (non-baseline) slurry mixture, calculate the aircontent that will achieve the desired density, based on the measurednon-foamed density, e.g., using the formula previously disclosed in thisdisclosure.

Second, enter the strength versus air content curves for the given ageof testing for the baseline mixture to determine the inherent strengthat that particular age and air content. For example, the 28 day strengthof the baseline mixture at 48% is 700 psi, e.g., 306 in FIG. 19.

Finally, compare the relative strengths of the non-foamed slurry ofinterest to the non-foamed baseline mixture at the same age. In thiscase, the baseline slurry yielded 6000 psi at 28 days at 0% air content,e.g., 300 in FIG. 19, versus 4500 psi for the other slurry at 0% air,e.g., 302 in FIG. 19. Estimate the final strength of the other slurry ata given air content & age, by multiplying the result from step 2 by theratio of the non-foamed results (700×4500/6000), calculated as 525 psi(e.g., FIG. 19).

Therefore, an embodiment of the present disclosure includes a method offormulating an annular grout composition, comprising mixing a firstbaseline mixture of a cementitious fly ash with water to about a 0.25water to fly ash ratio, wherein the first baseline mixture is dividedinto at least three sub-mixtures including one sub-mixture with no addedair content and two sub-mixtures with different air contents; measuringfluid density, penetration resistance and compressive strength of thesub-mixtures for at least two different times post mixing; mixing asecond mixture of at least one cementitious fly ash with water with noadditional air content; measuring fluid density, penetration resistanceand compressive strength of the second mixture for at least twodifferent time post mixing; calculating air content necessary to achievea specific density for a third mixture of cementitious fly ash withwater; and calculating a compressive strength for the third mixture at aspecific age and air content using data from the first baseline mixtureand the second mixture.

In some embodiments, a filler of non-cementitious fly ash, or anypreviously discussed filler or suitable filler, e.g., water reducers,set retarders, etc., may be included in the mixtures. In embodiments,the first baseline mixture may be mixed prior to dividing intosub-mixtures (e.g., for addition of air) or each first baselinesub-mixture may be mixed independently of each other. In an embodiment,the first baseline mixture may be mixed to a water to fly ash ratiobetween about 0.20 and about 0.30, to between about 0.22 and about 0.28,to between about 0.23 and about 0.26. In some embodiments, the water tofly ash ratio is mixed to less than 0.29, less than 0.28, to less than0.27, to less than 0.26, to less than 0.25, to less than 0.24, to lessthan 0.23. In some embodiments, the water to fly ash ratio is mixed togreater than 0.21, greater than 0.22, to greater than 0.23, to greaterthan 0.24, to greater than 0.25, to greater than 0.26.

Compositions for Caisson Construction and Methods of Utilizing the Same

The present disclosure also discloses a high-performance composition,generating high strengths, suitable for replacement of traditionalconcrete in specific applications of building construction. In anembodiment, the use of chemical retarders, and potentiallywater-reducers admixtures will accomplish structural requirements forthis improved composition. In some embodiments, traditional andnon-traditional aggregates might be used in the mixture matrix to reduceshrinkage and material costs.

Traditional Portland-cement based concrete for drilled-pier and caissonconstruction for building foundations is typically specified to have adesign strength of 3000-4000 psi in 28 days. Since freeze-thawprotection is generally not required, the traditional concrete istypically not air-entrained and high slumps (5-8″ or greater) arerequired to ensure proper consolidation, since internal vibration is notpossible at the greater depths of the caissons.

One composition of the present disclosure creates a cost-effectivealternative to traditional concrete for caisson construction by usingfly ash. The use of fly ash as alternative to Portland-based cementallows on-site batching with volumetric mixing trucks and eliminates alot of challenges of caisson construction with traditional concretedelivered in mixer-trucks. Caisson construction generally refers to theuse of deep foundation support that is constructed by placing freshconcrete and reinforcing steel into a drilled shaft. Caissons, which arecapable of supporting high, concentrated loads, are typically used toset piers for bridges, underpasses, structural supports, as well as inslide prevention applications.

Mixtures can be designed by first testing a caisson composition atvarious water contents, to determine early and long-term strengths, as afunction of fluidity required for normal caisson construction. Variousdosages of set retarder and water retarders can be tested to determinethe concentration required for reasonable constructability in the field,i.e., reasonably set time. In addition, in some embodiments an aggregatemay be included in the caisson composition.

After arriving at a desired composition, the incorporation of varyingair contents can be tested accounting for water/fly ash ratios to reacha required strength and fluidity for placement.

One of the benefits of the presently disclosed caisson composition whencoupled with on-site mixing trucks is that the exact amount of materialto fill a caisson is on-site, ready to be mixed & placed when drillingoperations require it. Worries about ready-mixed concrete being stuck intraffic or being on-site too long, resulting in rejection of theconcrete batch are eliminated.

For small projects, and not requiring a concrete-pump truck to placematerial in high-groundwater conditions, these volumetric trucks canreadily be driven to discharge directly into each caisson hole.Alternately, they could remain parked by the concrete-pump truck,discharging into the receiving hopper as numerous concrete trucks wouldnormally do.

Other significant benefits of the presently disclosed caissoncomposition is that the mixing truck and concrete pump truck can beparked in an out of the way location; continuous supplies of water andfly ash can be provided by a nearby fire hydrant and one or more bulkfly ash tankers. On secure sites; the mixing-truck can remain on-sitefor several days, with only the replenishing of fly ash materials in thebulk storage required.

Another significant benefit of the presently disclosed caissoncomposition is the reduction is shrinkage that occurs during (e.g.,chemical) and after (e.g., drying) hardening. For example, aPortland-cement paste has a chemical shrinkage of between 1% and 2%. Bycontrast, a cementitious fly ash paste of the present disclosure has achemical shrinkage of between 0.03% and 0.05% or less. For example,Portland-cement concrete has a drying shrinkage of between 0.04% and0.06% after 28 days. By contrast, a cementitious fly ash composition ofthe present disclosure has a drying shrinkage of between 0.001% and0.002% or less. Normal methods to reduce shrinkage include using morerock or larger size rock in a traditional concrete composition and usinga low water to traditional cement ratio. Surprisingly, the caissoncomposition of the present disclosure reduced shrinkage as compared withtraditional concrete without using traditional methods to reduceshrinkage.

In an embodiment, a composition for caisson construction comprisesbetween 0.0001% and 10% air by volume; between 60%-95% cementitious flyash by weight; between 5%-30% water by weight; and between 0.01% and 2%set retarder by weight, wherein the composition has compressive strengthof between 3000 and 5000 psi at seven days, a compressive strength ofbetween 4000 and 8000 psi at 28 days, and a density of between 100 and150 pcf.

The air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. In someembodiments, the presently disclosed caisson composition can include acellular foam to produce a high-strength material capable of freeze-thawresistance for external applications and/or to significantly lower theunit weight of the composition, making it suitable as a substitute fortraditional lightweight concrete for interior, elevated floor slabs. Inthis configuration, the lightweight, foamed high-strength compositionwould provide lower dead-loads in building, increased fire-resistance,increased insulation-value, and sound-proofing if used as walls betweendwelling units.

In some embodiments, the air content may be determined by the followingformula using wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$

In other embodiments, the air content can be determined using ASTM C231.In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur prior to addition of water, afteraddition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and possible filler) with water but prior to applying thecomposition to the void.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. Suitable cellular foam isavailable from a variety of sources, e.g., Cellular Concrete, LLC;Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and/or filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content. In some embodiments, the finalair content of the composition will be between about 0.001% and about15%, between about 0.01% and about 13%, between about 0.1% and about10%, between about 1.0% and about 8%, between about 2% and about 6%,between about 0.1% and about 5%, between about 0.1% and about 2%,between about 4% and about 10%, between about 4% and about 8%. In someembodiments, the composition does not contain any additional aircontent, i.e., the composition is not purposefully air entrained.

In some embodiments, the final air content will be greater than 0.1%,greater than 1%, greater than 2%, greater than 4%, greater than 6%,greater than 8%, greater than 10%, greater than 12%.

In other embodiments, the final air content of the composition will beless than 15%, less than 13%, less than 10%, less than 8%, less than 6%,less than 4%, less than 2%, less than 1%, less than 0.1%, less than0.01%.

In an embodiment of the presently disclosure caisson composition, thecementitious fly ash is Class C fly ash as defined by ASTM C618 or thestandards of a local agency. In other embodiments of the presentdisclosure, the cementitious fly ash can have cementitious propertieswithout qualifying as Class C fly ash under ASTM C618 or an equivalentstandard. A cementitious fly ash of the present disclosure is a fly ashthat sets (e.g., solidifies to 4 psi) within about thirty minutes at awater content of 30% by weight when water and cementitious fly ash arethe only ingredients.

In an embodiment of the present disclosure, a composition has betweenabout 60% and about 95% cementitious fly ash, between about 65% andabout 90% cementitious fly ash, between about 65% and about 85%cementitious fly ash, between about 70% cementitious fly ash and about80% cementitious fly ash, between about 60% and about 80% cementitiousfly ash, and between about 70% and about 90% cementitious fly ash.

In some embodiments of the present disclosure, a composition has lessthan about 95% cementitious fly ash, less than about 90% cementitiousfly ash, less than about 85% cementitious fly ash, less than about 80%cementitious fly ash, less than about 75% cementitious fly ash, lessthan about 70% cementitious fly ash, less than about 65% cementitiousfly ash or less than about 60% cementitious fly ash. In additionalembodiments of the present disclosure, the composition has greater thanabout 60% cementitious fly ash, greater than about 65% cementitious flyash, cementitious fly ash, greater than about 70% cementitious fly ash,greater than about 75% cementitious fly ash, greater than about 80%cementitious fly ash, greater than about 85% cementitious fly ash,greater than about 90% cementitious fly ash, or greater than about 95%cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. In an embodiment of the present disclosure, a composition hasa the water content of between about 5% and about 30%, between about 10%and about 25%, between about 15% and about 20%, between about 5% andabout 15%, between about 5% and about 20%, between about 15% and about25%. In additional embodiments, a composition has greater than about 5%water, greater than about 10% water, greater than about 15% water,greater than about 20% water, or greater than about 25% water. In otherembodiments, a composition has less than about 30% water, less thanabout 25% water, less than about 20% water, less than about 18% water,less than about 15% water, less than about 10% water, or less than about22% water. Any water included with additional ingredients, e.g., aqueouswater retarders, foaming agents, etc. under the circumstancesencountered in the field by the inventors has been negligible incomparison to the primary batch water and therefore has not beenincluded in the above calculations. Depending on the actual watercontent of the additional ingredients used it may be necessary toconsider the additional water in the final water concentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, aggregate, or recycled versionthereof. Determination of the filler material can be based on economics,availability, city, county and/or state specifications, or on thedesired properties of the composition, e.g., desired setting time,flowability, or final compressive strength.

In an embodiment, a composition of the present disclosure will havebetween about 1% and about 25% filler, between about 5% and about 20%filler, between about 10% and about 15% filler, between about 1% andabout 10% filler, between about 1% and about 5%, between about 5% andabout 10%, between about 5% and about 15%, between about 10% and about20%. In certain embodiments, a composition of the present disclosurewill have less than about 25% filler, less than about 20% filler, lessthan about 15% filler, less than about 10% filler, less than about 5%filler, less than about 1% filler. In still other embodiments, acomposition of the present disclosure will have greater than about 1%filler, greater than about 5% filler, greater than about 10% filler,greater than about 15% filler, greater than about 20% filler, greaterthan about 25% filler, or greater than about 8% filler.

Caisson compositions will comprise a set retarder in most embodiments. Aset retarder is a compound capable of delaying the set time of thecomposition. In certain embodiments, delaying the set time is necessaryto allow a caisson composition to completely fill a caisson beforesetting and keeping the mixture fluid in the pump between fillings. Anexample of a set retarder may be citric acid or borax, or a combinationthereof. In certain embodiments, the set retarder is liquid while inother embodiments the set retarder is a powder. An appropriate setretarder will be well known to a person of ordinary skill in the art.

In an embodiment, the concentration of set retarder is between about0.01% and about 3%, between about 0.01% and about 2% between about 0.05%and about 2.5%, between about 0.1% and about 2%, between about 0.5% andabout 1.5%, between about 0.0001% and about 1.0%. In some embodiments,the set retarder is greater than about 0.001%, is greater than about0.01% is greater than about 0.05%, is greater than about 0.1%, isgreater than about 0.5%, is greater than about 1.0%, is greater thanabout 1.5%, or is greater than about 2.0%. In certain embodiments, theset retarder is less than about 3.0%, less than about 2.5%, less thanabout 2.0%, less than about 1.5%, less than about 1.0%, less than about0.5%, less than about 0.3%, less than about 0.1%, less than about 0.01%,less than about 0.001%.

In some embodiments, the composition may further comprise a waterreducer. Water reducers may be used when a higher final strength isdesired at a specified density and fluidity. In some embodiments thewater reducer will be powder while in other embodiments it will be aliquid water reducer. In an embodiment, the water reducer is CHRYSO 256(high range) or 380 (midrange) or similar composition (CHRYSO, Inc.,1611 State Hwy 276, Rockwall, Tex. 75032). A water reducer is a chemical(e.g., chemical composition) that allows a mixture to maintain the samefluidity with less water or more fluidity with the same amount of water.

In an embodiment, the concentration of the water reducer is betweenabout 0.01% and about 3%, between about 0.01% and about 2% between about0.05% and about 2.5%, between about 0.1% and about 2%, between about0.5% and about 1.5%, between about 0.0001% and about 1.0%. In someembodiments, the water reducer is greater than about 0.001%, is greaterthan about 0.01% is greater than about 0.05%, is greater than about0.1%, is greater than about 0.5%, is greater than about 1.0%, is greaterthan about 1.5%, or is greater than about 2.0%. In certain embodiments,the water reducer is less than about 3.0%, less than about 2.5%, lessthan about 2.0%, less than about 1.5%, less than about 1.0%, less thanabout 0.5%, less than about 0.3%, less than about 0.1%, less than about0.01%, less than about 0.001%.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. For example, the larger thecaisson or the slower the pump rate, the longer the set time necessaryto complete filling the caisson before the composition sets. In someembodiments, the set time of the caisson composition is determined bymeasuring penetration resistance with a pocket penetrometer (e.g., witha resistance of 4 psi as typically used in standard ASTM WK 27337) orcement setting time standard ASTM C403. In an embodiment of the presentdisclosure, the set time for a composition can be between about 60minutes and about 8 hours, between about 2 hours and about 7 hours,between about 3 hours and about 6 hours. In additional embodiments, acomposition has a set time of less than 10 hours, of less than about 9hours, of less than about 8 hours, of less than about 7 hours, of lessthan about 6 hours, of less than about 5 hours, of less than about 4hours, of less than about 3 hours, of less than about 2 hours or of lessthan about 1 hour. In other embodiments, a composition has a set time ofgreater than about 2 hours, of greater than about 3 hours, of greaterthan about 4 hours, of greater than about 5 hours, of greater than about6 hours, of greater than about 7 hours, of greater than about 8 hours,or of greater than about 9 hours.

Caisson compositions of the present disclosure will have a range ofcompressive strengths at various times after the addition of acomposition to a caisson void depending on the desired properties of thecomposition.

In certain embodiments, the compressive strength is measured at 1 day, 3days, 7 days and 28 days where the 28 day measurement is considered thefinal compressive strength. In other embodiments, the compressivestrength is measured more often at smaller intervals or less often atlarger intervals. In some embodiments, the compressive strength ismeasured at 90 days.

In an embodiment, the compressive strength (e.g., tested by ASTM C31) ofa caisson composition of the present disclosure at seven days will bebetween about 3000 psi and about 6000 psi, between 3000 psi and 5000psi, between about 3500 psi and about 5500 psi, between about 4000 psiand about 5000 psi, between about 3500 psi and about 5000 psi, betweenabout 4000 psi and about 6000 psi, between about 3000 psi and about 4000psi. In additional embodiments, the compressive strength of the caissoncomposition at seven days will be greater than about 2500 psi, will begreater than about 3000 psi, will be greater than about 3500 psi, willbe greater than about 4500 psi, will be greater than about 5000 psi,will be greater than about 5500 psi, will be greater than about 6000psi. In an embodiment, the compressive strength of a caisson compositionof the present disclosure at seven days will be less than about 7000psi, less than about 6500 psi, less than about 6000 psi, less than about5500 psi, less than about 5000 psi, less than about 4500 psi, less thanabout 4000 psi, less than 3000 psi, or less than about 8000 psi.

In an embodiment, the compressive strength of a caisson composition ofthe present disclosure at 28 days will be between about 4000 psi andabout 8000 psi, between about 5000 psi and about 7000 psi, between about7000 psi and about 8000 psi, between about 7000 psi and about 10000 psi,between about 9000 psi and about 11000 psi, between about 5000 psi andabout 8000 psi, between about 5000 psi and about 7000 psi. In additionalembodiments, the compressive strength of the caisson composition at 28days will be greater than about 4500 psi, will be greater than about5000 psi, will be greater than about 6000 psi, will be greater thanabout 7000 psi, will be greater than about 8000 psi, will be greaterthan about 9000 psi, or will be greater than about 10000 psi. In certainembodiments, the compressive strength of the caisson composition at 28days will be less than about 11000 psi, less than about 10000 psi, lessthan about 9000 psi, less than about 8000 psi, less than about 7000 psi,less than about 6000 psi, less than about 5000 psi, or less than 4500psi.

In certain embodiments of the present disclosure, a suitable caissoncomposition can be defined by the water to fly ash ratio, e.g., whenusing no filler, when using non-cementitious fly ash filler, or othersuitable filler like sand. In certain embodiments, the water to fly ashratio will be a water to cementitious fly ash plus additionalnon-cementitious fly ash filler ratio.

In certain embodiments, a composition can have a range of water to flyash ratios depending on the water demand of the fly ash (or includedfiller), the desired flowability, the desired setting time and thedesired final compressive strength. In certain embodiments, the water tofly ash ratio of a composition (W/FA) is between about 0.10 and about0.30, between about 0.15 and about 0.25, between about 0.2 and about0.25, between about 0.2 and about 0.3, between about 0.1 and about 0.2or between about 0.05 and about 0.2. In additional embodiments, thewater to fly ash ratio of a composition is greater than about 0.1,greater than about 0.15, greater than about 0.2, greater than about0.25. In other embodiments, the water to fly ash ratio is less thanabout 0.35, less than about 0.3, less than about 0.25, less than about0.2, less than about 0.15, less than about 0.1.

In certain embodiments of the present disclosure, a caisson compositiondoes not include one or more of the following: does not include a waterreducer, does not include Portland cement, does not include a setretarder, does not include any cementitious material other thancementitious fly ash, does not include a filler, does not includeaggregate, does not include gravel, does not include CaCO₃ or lime otherthan that present in the cementitious fly ash and/or filler, or does notinclude sand. Furthermore, a composition of the present disclosure doesnot include native soils in some embodiments.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611.

The density of the caisson composition is important in certainembodiments. For example, the density is greater than water to displacewater in the void.

In embodiments, a composition of the present disclosure has a unitweight of between about 100 pcf and about 150 pcf, of between about 110pcf and about 140 pcf, between about 120 pcf and about 130 pcf, betweenabout 100 pcf and about 120 pcf, between about 100 pcf and about 130pcf, between about 120 and 140 pcf, between about 120 and 150 pcf. Inother embodiments, the unit weight of a composition is greater thanabout 90 pcf, greater than about 100 pcf, greater than about 110 pcf,greater than about 120 pcf, greater than about 130 pcf, greater thanabout 140 pcf, or greater than about 150 pcf. In still otherembodiments, a composition has a unit weight of less than about 160 pcf,of less than about 150 pcf, of less than about 140 pcf, of less thanabout 130 pcf, of less than about 120 pcf, of less than about 110 pcf,of less than about 100 pcf or of less than about 90 pcf.

One unexpected advantage of the presently disclosed caisson compositionis that it undergoes significantly less shrinkage than traditionalconcrete. In embodiments of the present invention, the chemicalshrinkage of caisson composition within 24 hours is between about0.0001% and about 0.01% by volume, between about 0.0005% and about0.005% by volume, between about 0.001% and about 0.003% by volume. Incertain embodiments, the shrinkage of the caisson composition within 24hours is less than about 0.05% by volume, less than about 0.03% byvolume, less than about 0.01% by volume, less than about 0.008% byvolume, less than about 0.005% by volume, less than about 0.003% byvolume or less than about 0.001% by volume.

In embodiments of the present invention, the drying shrinkage of caissoncomposition at 28 days is between about 0.0001% and about 0.01% byvolume, between about 0.0005% and about 0.005% by volume, between about0.001% and about 0.003% by volume. In certain embodiments, the shrinkageof the caisson composition at 28 days is less than about 0.05% byvolume, less than about 0.03% by volume, less than about 0.01% byvolume, less than about 0.008% by volume, less than about 0.005% byvolume, less than about 0.003% by volume or less than about 0.001% byvolume.

The present disclosure also contemplates a method of determining acaisson composition for filling a void comprising: identifying at leastone fly ash for use in the composition; determining a water demand ofeach fly ash within the composition; calculating a water demand for thecomposition; determining a compressive strength for the composition;determining the amount of air content necessary for the composition tohave a compressive strength of between 3000 and 5000 psi at seven days,between 4000 psi and 8000 psi at 28 days, and a density of between 100and 150 pcf; determining the time necessary to fill the void; anddetermining the concentration of set retarder necessary to delay thecomposition from setting in less time than necessary to fill the void.In an embodiment of the present disclosure a reference to fill the voidmeans completing installation of a particular composition by filling thetargeted space.

The determination of suitable fly ash, water demand, compressivestrength, air content, density, time to fill the void, and theconcentration of set retarder can be accomplished as discussed elsewherein this application.

The present disclosure also contemplates a method of manufacturing acaisson comprising: determining the time necessary to fill the void;adding water and set retarder to a cementitious fly ash to make a wetmixture; adding air to the wet mixture, wherein the composition has acompressive strength of between 3000 and 5000 psi at seven days, acompressive strength of between 4000 psi and 8000 psi at 28 days, and adensity of between 100 and 150 pcf; and adding the composition to thevoid.

Additional Compositions as Alternative to High-Strength Concrete forConstruction and Method of Utilizing the Same

The present invention also discloses a high-performance composition,generating high strengths, suitable for replacement of traditionalconcrete in applications of building construction. Like for thepreviously discussed caisson composition, the use of chemical retarders,and water-reducers admixtures can help to meet structural requirementsfor this construction composition. In some instances, traditional coarseaggregates can be used in the construction composition.

High strength concrete is typically defined as having a design strengthof 6000 psi or higher. The presently disclosed construction compositioncreates a cost-effective alternative to traditional high-strengthconcrete (design strengths of 6000 psi and greater) for use in generalbuilding-construction wherever concrete is formed and placed, withoutnecessarily needing hand finishing of the final horizontal surface. Someexamples of potential use include formed columns, beams, and verticalwalls. A construction composition may also be used in pre-cast concretemanufacturing plants.

A composition for construction as presently disclosed will be similar tothe previously disclosed caisson composition but may have a higher finalcompressive strength (e.g., for simplicity the caisson section of thisapplication is incorporated herein in its entirety.) In someembodiments, a filler may include a by-product of sand & gravelprocessing.

Like the caisson composition, the presently disclosed constructioncomposition can be modified to include cellular foam to produce ahigh-strength material capable of freeze-thaw resistance for externalapplications. Alternately, higher dosages of this same foam could beadded to significantly lower the unit weight of the constructioncomposition, making it suitable as a substitute for traditionallightweight concrete for interior, elevated floor slabs. Alternately,traditional lightweight coarse aggregates can be used with the foamed,construction composition as the binder mortar. In these embodiments, thelightweight, foamed construction composition can provide lowerdead-loads in building, increased fire-resistance, increasedinsulation-value, and sound-proofing if used as walls between dwellingunits.

In an embodiment, a composition for construction comprises between0.0001% and 10% air by volume; between 60%-95% cementitious fly ash byweight; between 5%-30% water by weight; and between 0.01% and 2% setretarder by weight, wherein the composition has compressive strength ofbetween 3500 and 6000 psi at seven days, a compressive strength ofbetween 5000 psi and 10000 psi at 28 days, and a density of between 100and 150 pcf.

Construction compositions of the present disclosure will have a range ofcompressive strengths at various times after setting.

In an embodiment, the compressive strength (e.g., tested by ASTM C31) ofa construction composition of the present disclosure at seven days willbe between about 3500 psi and about 6000 psi, between 3000 psi and 5000psi, between about 3500 psi and about 5500 psi, between about 4000 psiand about 5000 psi, between about 3500 psi and about 5000 psi, betweenabout 4000 psi and about 6000 psi, between about 3000 psi and about 4000psi. In additional embodiments, the compressive strength of the caissoncomposition at seven days will be greater than about 2500 psi, will begreater than about 3000 psi, will be greater than about 3500 psi, willbe greater than about 4500 psi, will be greater than about 5000 psi,will be greater than about 5500 psi, will be greater than about 6000psi. In an embodiment, the compressive strength of a caisson compositionof the present disclosure at seven days will be less than about 7000psi, less than about 6500 psi, less than about 6000 psi, less than about5500 psi, less than about 5000 psi, less than about 4500 psi, less thanabout 4000 psi, less than 3000 psi, or less than about 8000 psi.

In an embodiment, the compressive strength of a construction compositionof the present disclosure at 28 days will be between about 5000 psi andabout 10000 psi, between about 6000 psi and about 9000 psi, betweenabout 7000 psi and about 8000 psi, between about 5000 psi and about 8000psi, between about 6000 psi and about 8000 psi, between about 7000 psiand about 10000 psi. In additional embodiments, the compressive strengthof the construction composition at 28 days will be greater than about5000 psi, will be greater than about 6000 psi, will be greater thanabout 7000 psi, will be greater than about 8000 psi, will be greaterthan about 9000 psi, will be greater than about 10000 psi, or will begreater than about 12000 psi. In certain embodiments, the compressivestrength of the construction composition at 28 days will be less thanabout 11000 psi, less than about 10000 psi, less than about 9000 psi,less than about 8000 psi, less than about 7000 psi, less than 6000 psi,or less than about 5500 psi.

The present disclosure also contemplates a method of determining aconstruction composition comprising: identifying at least one fly ashfor use in the composition; determining a water demand of each fly ashwithin the composition; calculating a water demand for the composition;determining a compressive strength for the composition; determining theamount of air content necessary for the composition to have acompressive strength of between 3500 and 6000 psi at seven days, acompressive strength of between 5000 psi and 10000 psi at 28 days, and adensity of between 100 and 150 pcf; determining the time necessary tocomplete installation of the composition; and determining theconcentration of set retarder necessary to delay the composition fromsetting in less time than necessary to complete installation of thecomposition.

The determination of suitable fly ash, water demand, compressivestrength, air content, density, time to fill the void, and theconcentration of set retarder can be accomplished as discussed elsewherein this application.

The present disclosure also contemplates a method of manufacturing abuilding element comprising: determining the time necessary to completeinstallation of the composition; adding water and set retarder to acementitious fly ash to make a wet mixture; adding air to the wetmixture, wherein the composition has a compressive strength of between3500 and 6000 psi at seven days, a compressive strength of between 5000psi and 10000 psi 28 days, and a density of between 100 and 150 pcf; andinstalling the composition.

Recycled Compositions and Methods of Utilizing the Same

The present disclosure also discloses a composition made of 100%recycled materials, that will achieve normal structural requirementsnormally achieved with Portland-cement. Like for the previouslydiscussed caisson composition, the use of chemical retarders, andwater-reducers admixtures can help to meet structural requirements forthis construction composition. In some instances, traditional coarseaggregates can be used in the construction composition.

Traditional Portland-cement based concrete has sometimes used recycledconcrete as coarse aggregates (gravel-sized) in the cement mixture.However, use of the ¼″ and smaller portions generated from crushing oldconcrete has not been widespread due to the high amount of flour-sized“fines” in the sand-size fraction of recycled concrete. Instead, virginor manufactured sands are traditionally used in Portland-cement basedconcrete. Traditionally, the high fines in recycled concrete “sand”caused a high-water demand in the mixture, which tends to lower thestrength of the mixture. Higher amounts of Portland cement would berequired to overcome this high water demand, and that is typicallyuneconomical when compared to using washed, virgin sands.

When concrete is recycled in traditional means, the “rock” is screenedfrom the “sand” size materials, for use in concrete production; the sandsize is typically wasted or sold as low-value fill. The processing costsof recycling concrete are typically charged to the salable rock fractionalone, which drives its relative cost up. By using all of the recycledconcrete fractions in the newly disclosed composition, lower aggregatecosts are realized, as well as lower fly ash and water volumes, due toan improved aggregate packing relationship (e.g., less voids to fillwith paste). In an embodiment, by using a water-reducing admixture,satisfactory strengths can be achieved, yet economically, using 100% ornearly 100% recycled materials.

In an embodiment, a recycled composition comprises between 0.0001% and10% air by volume; between 15%-35% cementitious fly ash by weight;between 5%-15% water by weight; between 50%-80% recycled filler andbetween 0.01% and 2% set retarder by weight, wherein the compositionsets in less than 4 hours and has a density of between 115 and 150 pcf.

The air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. In someembodiments, the air content may be determined by the following formulausing wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$

In other embodiments, the air content can be determined using ASTM C231.In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur prior to addition of water, afteraddition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and filler) with water but prior to applying the composition to thevoid.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. Suitable cellular foam isavailable from a variety of sources, e.g., Cellular Concrete, LLC;Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content. In some embodiments, the finalair content of the composition will be between about 0.001% and about15%, between about 0.01% and about 13%, between about 0.1% and about10%, between about 1.0% and about 8%, between about 2% and about 6%,between about 0.1% and about 5%, between about 0.1% and about 2%,between about 4% and about 10%, between about 4% and about 8%. In someembodiments, the composition does not contain any additional aircontent, i.e., the composition is not purposefully air entrained.

In some embodiments, the final air content will be greater than 0.1%,greater than 1%, greater than 2%, greater than 4%, greater than 6%,greater than 8%, greater than 10%, greater than 12%.

In other embodiments, the final air content of the composition will beless than 15%, less than 13%, less than 10%, less than 8%, less than 6%,less than 4%, less than 2%, less than 1%, less than 0.1%, less than0.01%.

In an embodiment of the presently disclosure recycled composition, thecementitious fly ash is Class C fly ash as defined by ASTM C618 or thestandards of a local agency. In other embodiments of the presentdisclosure, the cementitious fly ash can have cementitious propertieswithout qualifying as Class C fly ash under ASTM C618 or an equivalentstandard. A cementitious fly ash of the present disclosure is a fly ashthat sets (e.g., solidifies to 4 psi) within about thirty minutes at awater content of 30% by weight when water and cementitious fly ash arethe only ingredients.

In an embodiment of the present disclosure, a recycled composition hasbetween about 15% and about 35% cementitious fly ash, between about 20%and about 30% cementitious fly ash, between about 15% and about 30%cementitious fly ash, between about 20% cementitious fly ash and about35% cementitious fly ash, between about 22% and about 28% cementitiousfly ash.

In some embodiments of the present disclosure, a composition has lessthan about 40% cementitious fly ash, less than about 35% cementitiousfly ash, less than about 30% cementitious fly ash, less than about 25%cementitious fly ash, less than about 20% cementitious fly ash, lessthan about 15% cementitious fly ash. In additional embodiments of thepresent disclosure, a recycled composition has greater than about 15%cementitious fly ash, greater than about 20% cementitious fly ash,greater than about 25% cementitious fly ash, greater than about 30%cementitious fly ash, greater than about 35% cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. In an embodiment of the present disclosure, a composition hasa the water content of between about 5% and about 15%, between about 7%and about 12%, between about 5% and about 10%, between about 10% andabout 15%. In additional embodiments, a composition has greater thanabout 3% water, greater than about 5% water, greater than about 7%water, greater than about 10% water, or greater than about 13% water. Inother embodiments, a composition has less than about 20% water, lessthan about 15% water, less than about 10% water, less than about 7%water, less than about 5% water. Any water included with additionalingredients, e.g., aqueous water retarders, foaming agents, etc. underthe circumstances encountered in the field by the inventors has beennegligible in comparison to the primary batch water and therefore hasnot been included in the above calculations. Depending on the actualwater content of the additional ingredients used it may be necessary toconsider the additional water in the final water concentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, aggregate, or recycled versionthereof. In some embodiments, the recycled filler is a recycledaggregate. In additional embodiments, the recycled aggregate is about100% recycled aggregate while in other embodiments the recycledaggregate is less than 100% recycled aggregate but greater than 50%recycled aggregate. In additional embodiments, the recycled aggregate is90% or 95% or 99% recycled aggregate. Determination of the fillermaterial can be based on economics, availability, city, county and/orstate specifications, or on the desired properties of the composition,e.g., desired setting time, flowability, or final compressive strength.

In an embodiment, a composition of the present disclosure will havebetween about 50% and about 80% filler, between about 55% and about 75%filler, between about 60% and about 50% filler, between about 50% andabout 60% filler, between about 50% and about 70%, between about 60% andabout 80%, between about 65% and about 80% filler. In certainembodiments, a composition of the present disclosure will have less thanabout 80% filler, less than about 75% filler, less than about 70%filler, less than about 65% filler, less than about 60% filler, lessthan about 55% filler. In still other embodiments, a composition of thepresent disclosure will have greater than about 50% filler, greater thanabout 55% filler, greater than about 60% filler, greater than about 65%filler, greater than about 70% filler, greater than about 75% filler, orgreater than about 80% filler.

Recycled compositions will comprise a set retarder in most embodiments.A set retarder is a compound capable of delaying the set time of thecomposition. In certain embodiments, delaying the set time is necessaryto allow a recycled composition to completely fill a void beforesetting. An example of a set retarder may be citric acid or borax, or acombination thereof. In certain embodiments, the set retarder is liquidwhile in other embodiments the set retarder is a powder. An appropriateset retarder will be well known to a person of ordinary skill in theart.

In an embodiment, the concentration of set retarder is between about0.01% and about 3%, between about 0.01% and about 2% between about 0.05%and about 2.5%, between about 0.1% and about 2%, between about 0.5% andabout 1.5%, between about 0.0001% and about 1.0%. In some embodiments,the set retarder is greater than about 0.001%, is greater than about0.01% is greater than about 0.05%, is greater than about 0.1%, isgreater than about 0.5%, is greater than about 1.0%, is greater thanabout 1.5%, or is greater than about 2.0%. In certain embodiments, theset retarder is less than about 3.0%, less than about 2.5%, less thanabout 2.0%, less than about 1.5%, less than about 1.0%, less than about0.5%, less than about 0.3%, less than about 0.1%, less than about 0.01%,less than about 0.001%.

In some embodiments, the composition may further comprise a waterreducer. Water reducers may be used when a higher final strength isdesired at a specified density and fluidity. In some embodiments thewater reducer will be powder while in other embodiments it will be aliquid water reducer. In an embodiment, the water reducer is CHRYSO 256(high range) or 380 (midrange) or similar composition. A water reduceris a chemical (e.g., chemical composition) that allows a mixture tomaintain the same fluidity with less water or more fluidity with thesame amount of water.

In an embodiment, the concentration of the water reducer is betweenabout 0.01% and about 3%, between about 0.01% and about 2% between about0.05% and about 2.5%, between about 0.1% and about 2%, between about0.5% and about 1.5%, between about 0.0001% and about 1.0%. In someembodiments, the water reducer is greater than about 0.001%, is greaterthan about 0.01% is greater than about 0.05%, is greater than about0.1%, is greater than about 0.5%, is greater than about 1.0%, is greaterthan about 1.5%, or is greater than about 2.0%. In certain embodiments,the water reducer is less than about 3.0%, less than about 2.5%, lessthan about 2.0%, less than about 1.5%, less than about 1.0%, less thanabout 0.5%, less than about 0.3%, less than about 0.1%, less than about0.01%, less than about 0.001%.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. For example, the larger thebuilding element or the slower the pump rate, the longer the set timenecessary to complete filling the building element before thecomposition sets. In some embodiments, the set time of the buildingelement composition is determined by measuring penetration resistancewith a pocket penetrometer (e.g., with a resistance of 4 psi astypically used in standard ASTM WK 27337) or cement setting timestandard ASTM C403. In an embodiment of the present disclosure, the settime for a composition can be between about 60 minutes and about 4hours, between about 1.5 hours and about 3.5 hours, between about 2hours and about 3 hours. In additional embodiments, a composition has aset time of less than 4 hours, of less than about 3 hours, of less thanabout 2 hours, of less than about 1.5 hours, of less than about 1 hour.In other embodiments, a composition has a set time of greater than about1 hours, of greater than about 1.5 hours, of greater than about 2 hours,of greater than about 2.5 hours, of greater than about 3 hours, ofgreater than about 4 hours.

Recycled compositions of the present disclosure will have a range ofcompressive strengths at various times after the addition of acomposition to a caisson void depending on the desired properties of thecomposition.

In certain embodiments, the compressive strength is measured at 1 day, 3days, 7 days and 28 days where the 28 day measurement is considered thefinal compressive strength. In other embodiments, the compressivestrength is measured more often at smaller intervals or less often atlarger intervals. In some embodiments, the compressive strength ismeasured at 90 days.

In an embodiment, the compressive strength (e.g., tested by ASTM C31) ofa recycled composition of the present disclosure at seven days will bebetween about 3500 psi and about 6000 psi, between about 3750 psi andabout 5500 psi, between about 4000 psi and about 5000 psi, between about3500 psi and about 5000 psi, between about 4000 psi and about 6000 psi,between about 5000 psi and about 6000 psi. In additional embodiments,the compressive strength of the recycled composition at seven days willbe greater than about 3000 psi, will be greater than about 3500 psi,will be greater than about 4000 psi, will be greater than about 4500psi, will be greater than about 5000 psi, will be greater than about5500 psi, will be greater than about 6000 psi. In an embodiment, thecompressive strength of a recycled composition of the present disclosureat seven days will be less than about 7000 psi, less than about 6500psi, less than about 6000 psi, less than about 5500 psi, less than about5000 psi, less than about 4500 psi, less than about 4000 psi, or lessthan about 8000 psi.

In an embodiment, the compressive strength of a recycled composition ofthe present disclosure at 28 days will be between about 5000 psi andabout 10000 psi, between about 6000 psi and about 9000 psi, betweenabout 7000 psi and about 8000 psi, between about 7000 psi and about10000 psi, between about 9000 psi and about 11000 psi, between about5000 psi and about 8000 psi, between about 5000 psi and about 7000 psi.In additional embodiments, the compressive strength of the recycledcomposition at 28 days will be greater than about 4500 psi, will begreater than about 5000 psi, will be greater than about 6000 psi, willbe greater than about 7000 psi, will be greater than about 8000 psi,will be greater than about 9000 psi, or will be greater than about 10000psi. In certain embodiments, the compressive strength of the recycledcomposition at 28 days will be less than about 11000 psi, less thanabout 10000 psi, less than about 9000 psi, less than about 8000 psi,less than about 7000 psi, less than about 6000 psi, or less than about5000 psi.

In certain embodiments of the present disclosure, a suitable recycledcomposition can be defined by the water to fly ash ratio, e.g., whenusing no filler, when using non-cementitious fly ash filler, or othersuitable filler like recycled aggregate. In certain embodiments, thewater to fly ash ratio will be a water to cementitious fly ash plusadditional non-cementitious fly ash filler ratio.

In certain embodiments, a composition can have a range of water to flyash ratios depending on the water demand of the fly ash (or includedfiller), the desired flowability, the desired setting time and thedesired final compressive strength. In certain embodiments, the water tofly ash ratio of a composition (W/FA) is between about 0.10 and about0.30, between about 0.15 and about 0.25, between about 0.2 and about0.25, between about 0.2 and about 0.3, between about 0.1 and about 0.2or between about 0.05 and about 0.2. In additional embodiments, thewater to fly ash ratio of a composition is greater than about 0.1,greater than about 0.15, greater than about 0.2, greater than about0.25. In other embodiments, the water to fly ash ratio is less thanabout 0.35, less than about 0.3, less than about 0.25, less than about0.2, less than about 0.15, less than about 0.1.

In certain embodiments of the present disclosure, a recycled compositiondoes not include one or more of the following: does not include a waterreducer, does not include Portland cement, does not include a setretarder, does not include any cementitious material other thancementitious fly ash, does not include a filler, does not includeaggregate, does not include gravel, does not include CaCO₃ or lime otherthan that present in the cementitious fly ash and/or filler, or does notinclude sand. Furthermore, a composition of the present disclosure doesnot include native soils in some embodiments.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611or spread as determined by D6103.

The density of the recycled composition is important in certainembodiments. In embodiments, a composition of the present disclosure hasa unit weight of between about 115 pcf and about 150 pcf, of betweenabout 120 pcf and about 145 pcf, between about 125 pcf and about 135pcf, between about 115 pcf and about 140 pcf, between about 115 pcf andabout 135 pcf, between about 125 pcf and 150 pcf, between about 120 pcfand 150 pcf. In other embodiments, the unit weight of a composition isgreater than about 90 pcf, greater than about 100 pcf, greater thanabout 110 pcf, greater than about 120 pcf, greater than about 130 pcf,greater than about 140 pcf, or greater than about 150 pcf. In stillother embodiments, a composition has a unit weight of less than about160 pcf, of less than about 150 pcf, of less than about 140 pcf, of lessthan about 130 pcf, of less than about 120 pcf, of less than about 110pcf, of less than about 100 pcf or of less than about 90 pcf.

The present disclosure also contemplates a method of determining arecycled composition for construction comprising: identifying at leastone fly ash for use in the composition; determining a water demand ofeach fly ash within the composition; calculating a water demand for thecomposition, including recycled filler; determining a compressivestrength for the composition; determining the amount of air contentnecessary for the composition to set is less than 4 hours and have adensity of between 115 pcf and 150 pcf; determining the time necessaryto finish a construction project; and determining the concentration ofset retarder necessary to delay the composition from setting in lesstime than necessary to finish the construction project.

The determination of suitable fly ash, water demand, compressivestrength, air content, density, time to finish the construction project,and the concentration of set retarder can be accomplished as discussedelsewhere in this application.

Compositions for Use as Wicking Layer and Methods of Utilizing the Same

This present disclosure additionally provides an economical,easy-to-install composition for use as wicking layer under concreteslabs, instead of the general industry recommended layer of compactedcrusher fines. The composition can use cementitious fly ash alone or incombination with an additional filler for better economy. In anembodiment, water-reducing admixtures are used to increase the strengthof the cementitious slurry, prior to foaming with a permeable,pre-formed, cellular foam, allowing higher air contents for even greatereconomy. The slab-wicking composition is placed & screeded to a uniformdepth, and is sufficiently hard the next day to allow foot-traffic, andsubsequent concrete placement when dry enough to wick.

With VOC-compliant flooring adhesives mandated for interiorapplications, vapor transmissions of moisture from and through concretefloor slabs is a critical issue for both successful adhesion of flooringmaterials, as well as to the construction schedule. If concrete slabsare placed directly on an effective vapor barrier, the concrete will dryout rather quickly to allow flooring adhesives. However, drying onlyoccurs from the top of slab; that results in greater drying shrinkage ofthe surface, which promotes slab curling, where the edges of eachconcrete slab raise up during the drying process. The loss of support atthe joints can lead to flexural cracking, as wheel loads cross thesejoints. Even without flexural cracking, the inherent flatness of theconcrete floor is lost, when slabs curl, due to differential dryingshrinkage.

Industry recommendations (ACI 302 11.11) are to install a minimum of 4″of crusher fines as a dry to almost-dry base, that will wick somemoisture away from the bottom surface of concrete. If the top surface iswell sealed to prevent moisture loss, fairly uniform curing and dryingshrinkage will occur throughout the depth of the concrete slab, hencereducing slab curling. However, it is often difficult to transportcrusher fines (often 135 pcf when compacted in-place), spread & compactthem, and have them stable to foot-traffic for rebar and concreteplacement, when the moisture content is almost dry because dry granularmaterials tend to ravel & shift.

In an embodiment of the present disclosure, a cementitious slurry isdelivered or manufactured on-site with cellular grout productionequipment. A cellular, pervious foam is added to the slurry, either inthe revolving drum mixer, or in an in-line mixing device. The cellular,pervious concrete (20-60 pcf) is then pumped to the point of placement,where it is easily screeded over forms to ensure a uniform depth, andflat subgrade for subsequent concrete placement.

In an embodiment, when the cellular, pervious concrete has gainedsufficient strength to handle foot traffic, installation of reinforcingsteel may begin. When the cellular concrete has dried out sufficientlyto provide adequate wicking of excess moisture from the concrete slab,concrete placement can begin using conventional methods. The pervious,cellular concrete will readily wick-away sufficient moisture to preventslab curling, however will dry out in similar time to concrete directlyon a vapor barrier, to allow vapor transmissions low enough for flooradhesives.

In an embodiment, a wicking composition comprises between 45% and 80%air by volume; between 70%-90% cementitious fly ash by weight; andbetween 10%-30% water by weight, wherein the composition sets in lessthan 4 hours, has a compressive strength of between 100 and 600 psiafter 7 days and has a density of between 20 and 60 pcf.

The air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. In someembodiments, the air content may be determined by the following formulausing wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$

In other embodiments, the air content can be determined using ASTM C231.In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur prior to addition of water, afteraddition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and filler) with water but prior to applying the composition to thevoid.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. Suitable cellular foam isavailable from a variety of sources, e.g., Cellular Concrete, LLC;Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. Whenwicking is a desired property, a pervious foam can be used. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content. In some embodiments, the finalair content of the composition will be between about 45% and about 80%,between about 50% and about 75%, between about 55% and about 70%,between about 45% and about 60%, between about 50% and about 60%,between about 60% and about 80%, between about 65% and about 75%.

In some embodiments, the final air content will be greater than 45%,greater than 50%, greater than 55%, greater than 60%, greater than 65%,greater than 75%, greater than 80%, greater than 85%.

In other embodiments, the final air content of the composition will beless than 85%, less than 80%, less than 75%, less than 70%, less than65%, less than 60%, less than 55%, less than 50%, less than 45%.

In an embodiment of the presently disclosure wicking composition, thecementitious fly ash is Class C fly ash as defined by ASTM C618 or thestandards of a local agency. In other embodiments of the presentdisclosure, the cementitious fly ash can have cementitious propertieswithout qualifying as Class C fly ash under ASTM C618 or an equivalentstandard. A cementitious fly ash of the present disclosure is a fly ashthat sets (e.g., solidifies to 4 psi) within about thirty minutes at awater content of 30% by weight when water and cementitious fly ash arethe only ingredients.

In an embodiment of the present disclosure, a wicking composition hasbetween about 70% and about 90% cementitious fly ash, between about 75%and about 85% cementitious fly ash, between about 70% and about 80%cementitious fly ash, between about 80% cementitious fly ash and about90% cementitious fly ash.

In some embodiments of the present disclosure, a composition has lessthan about 90% cementitious fly ash, less than about 85% cementitiousfly ash, less than about 80% cementitious fly ash, less than about 75%cementitious fly ash, less than about 70% cementitious fly ash, lessthan about 65% cementitious fly ash. In additional embodiments of thepresent disclosure, a wicking composition has greater than about 70%cementitious fly ash, greater than about 75% cementitious fly ash,greater than about 80% cementitious fly ash, greater than about 85%cementitious fly ash, greater than about 90% cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. In an embodiment of the present disclosure, a composition hasa the water content of between about 10% and about 30%, between about15% and about 25%, between about 10% and about 20%, between about 20%and about 30%. In additional embodiments, a composition has greater thanabout 10% water, greater than about 15% water, greater than about 20%water, greater than about 25% water, or greater than about 30% water. Inother embodiments, a composition has less than about 30% water, lessthan about 25% water, less than about 20% water, less than about 15%water, less than about 10% water. Any water included with additionalingredients, e.g., aqueous water retarders, foaming agents, etc. underthe circumstances encountered in the field by the inventors has beennegligible in comparison to the primary batch water and therefore hasnot been included in the above calculations. Depending on the actualwater content of the additional ingredients used it may be necessary toconsider the additional water in the final water concentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, aggregate, or recycled versionthereof. Determination of the filler material can be based on economics,availability, city, county and/or state specifications, or on thedesired properties of the composition, e.g., desired setting time,flowability, or final compressive strength.

Presently disclosed compositions will comprise a set retarder in someembodiments. A set retarder is a compound capable of delaying the settime of the composition. In certain embodiments, delaying the set timeis necessary to allow a composition to be installed before setting. Anexample of a set retarder may be citric acid or borax, or a combinationthereof. In certain embodiments, the set retarder is liquid while inother embodiments the set retarder is a powder. An appropriate setretarder will be well known to a person of ordinary skill in the art.

In an embodiment, the concentration of set retarder is between about0.01% and about 3%, between about 0.01% and about 2% between about 0.05%and about 2.5%, between about 0.1% and about 2%, between about 0.5% andabout 1.5%, between about 0.0001% and about 1.0%. In some embodiments,the set retarder is greater than about 0.001%, is greater than about0.01% is greater than about 0.05%, is greater than about 0.1%, isgreater than about 0.5%, is greater than about 1.0%, is greater thanabout 1.5%, or is greater than about 2.0%. In certain embodiments, theset retarder is less than about 3.0%, less than about 2.5%, less thanabout 2.0%, less than about 1.5%, less than about 1.0%, less than about0.5%, less than about 0.3%, less than about 0.1%, less than about 0.01%,less than about 0.001%.

In some embodiments, the composition may further comprise a waterreducer. Water reducers may be used when a higher final strength isdesired at a specified density and fluidity. In some embodiments thewater reducer will be powder while in other embodiments it will be aliquid water reducer. In an embodiment, the water reducer is CHRYSO 256(high range) or 380 (midrange) or similar composition. A water reduceris a chemical (e.g., chemical composition) that allows a mixture tomaintain the same fluidity with less water or more fluidity with thesame amount of water.

In an embodiment, the concentration of the water reducer is betweenabout 0.01% and about 3%, between about 0.01% and about 2% between about0.05% and about 2.5%, between about 0.1% and about 2%, between about0.5% and about 1.5%, between about 0.0001% and about 1.0%. In someembodiments, the water reducer is greater than about 0.001%, is greaterthan about 0.01% is greater than about 0.05%, is greater than about0.1%, is greater than about 0.5%, is greater than about 1.0%, is greaterthan about 1.5%, or is greater than about 2.0%. In certain embodiments,the water reducer is less than about 3.0%, less than about 2.5%, lessthan about 2.0%, less than about 1.5%, less than about 1.0%, less thanabout 0.5%, less than about 0.3%, less than about 0.1%, less than about0.01%, less than about 0.001%.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. In some embodiments, the settime of the wicking composition is determined by measuring penetrationresistance with a pocket penetrometer (e.g., with a resistance of 4 psias typically used in standard ASTM WK 27337) or cement setting timestandard ASTM C403. In an embodiment of the present disclosure, the settime for a composition can be between about 60 minutes and about 2hours, between about 1.5 hours and about 3.5 hours, between about 2hours and about 3 hours. In additional embodiments, a composition has aset time of less than 4 hours, of less than about 3 hours, of less thanabout 2 hours, of less than about 1.5 hours, of less than about 1 hour.In other embodiments, a composition has a set time of greater than about1 hours, of greater than about 1.5 hours, of greater than about 2 hours,of greater than about 2.5 hours, of greater than about 3 hours, ofgreater than about 4 hours.

Wicking compositions of the present disclosure will have a range ofcompressive strengths at various times after the addition of acomposition to a floor.

In certain embodiments, the compressive strength is measured at 1 day, 3days, 7 days and 28 days where the 28 day measurement is considered thefinal compressive strength. In other embodiments, the compressivestrength is measured more often at smaller intervals or less often atlarger intervals. In some embodiments, the compressive strength ismeasured at 90 days. In an embodiment, the bearing penetration orcapacity resistance of a composition is measured at 1 day, 7 days and 28days using ASTM WK 27337 or C403.

In an embodiment, the compressive strength (e.g., tested by ASTM C495)of a wicking composition of the present disclosure at seven days will bebetween about 100 psi and about 600 psi, between about 200 psi and about500 psi, between about 300 psi and about 400 psi, between about 100 psiand about 300 psi, between about 400 psi and about 600 psi, betweenabout 300 psi and about 600 psi. In additional embodiments, thecompressive strength of the wicking composition at seven days will begreater than about 100 psi, will be greater than about 200 psi, will begreater than about 300 psi, will be greater than about 400 psi, will begreater than about 500 psi, will be greater than about 600 psi, will begreater than about 700 psi. In an embodiment, the compressive strengthof a wicking composition of the present disclosure at seven days will beless than about 700 psi, less than about 600 psi, less than about 500psi, less than about 400 psi, less than about 300 psi, less than about200 psi, less than about 100 psi,

In an embodiment, the compressive strength of a wicking composition ofthe present disclosure at 28 days will be between about 150 psi andabout 900 psi, between about 200 psi and about 800 psi, between about300 psi and about 700 psi, between about 400 psi and about 600 psi,between about 150 psi and about 400 psi, between about 400 psi and about800 psi, between about 500 psi and about 800 psi. In additionalembodiments, the compressive strength of a wicking composition at 28days will be greater than about 100 psi, will be greater than about 200psi, will be greater than about 300 psi, will be greater than about 400psi, will be greater than about 500 psi, will be greater than about 600psi, or will be greater than about 700 psi. In certain embodiments, thecompressive strength of a wicking composition at 28 days will be lessthan about 800 psi, less than about 700 psi, less than about 600 psi,less than about 500 psi, less than about 400 psi, less than about 300psi, or less than about 200 psi.

In certain embodiments of the present disclosure, a suitable wickingcomposition can be defined by the water to fly ash ratio, e.g., whenusing no filler, when using non-cementitious fly ash filler, or othersuitable filler like recycled aggregate. In certain embodiments, thewater to fly ash ratio will be a water to cementitious fly ash plusadditional non-cementitious fly ash filler ratio.

In certain embodiments, a composition can have a range of water to flyash ratios depending on the water demand of the fly ash (or includedfiller), the desired flowability, the desired setting time and thedesired final compressive strength. In certain embodiments, the water tofly ash ratio of a composition (W/FA) is between about 0.10 and about0.30, between about 0.15 and about 0.25, between about 0.2 and about0.25, between about 0.2 and about 0.3, between about 0.1 and about 0.2or between about 0.05 and about 0.2. In additional embodiments, thewater to fly ash ratio of a composition is greater than about 0.1,greater than about 0.15, greater than about 0.2, greater than about0.25. In other embodiments, the water to fly ash ratio is less thanabout 0.35, less than about 0.3, less than about 0.25, less than about0.2, less than about 0.15, less than about 0.1.

In certain embodiments of the present disclosure, a wicking compositiondoes not include one or more of the following: does not include a waterreducer, does not include Portland cement, does not include a setretarder, does not include any cementitious material other thancementitious fly ash, does not include a filler, does not includeaggregate, does not include gravel, does not include CaCO₃ or lime otherthan that present in the cementitious fly ash and/or filler, or does notinclude sand.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611or spread as determined by D6103.

The density of the wicking composition is important in certainembodiments. In embodiments, a composition of the present disclosure hasa unit weight of between about 20 pcf and about 60 pcf, of between about30 pcf and about 50 pcf, between about 40 pcf and about 50 pcf, betweenabout 20 pcf and about 40 pcf, between about 30 pcf and about 50 pcf. Inother embodiments, the unit weight of a composition is greater thanabout 15 pcf, greater than about 20 pcf, greater than about 30 pcf,greater than about 40 pcf, greater than about 50 pcf, greater than about60 pcf, or greater than about 25 pcf. In still other embodiments, acomposition has a unit weight of less than about 60 pcf, of less thanabout 50 pcf, of less than about 40 pcf, of less than about 35 pcf, ofless than about 30 pcf, of less than about 25 pcf, of less than about 20pcf or of less than about 45 pcf.

Compositions for Pavement Patching and Methods of Utilizing the Same

The present disclosure also reveals a composition for use as a moredurable temporary pavement patch than traditional “cold-mix” asphaltproducts currently in wide use. In addition to an improvement indurability, the compositions are also less expensive than otherhigh-strength, fast-setting mixtures using Portland cement and otherhydraulic cement binders. The high-strength patch of the presentdisclosure can be driven on within a few hours. In an embodiment, aby-product of sand & gravel processing can also be incorporated into themain patch mixture, for economy. In additional embodiments, small-sizegravel, sand, or other aggregates can be sprinkled on to the patchsurface, before final set occurs, in increase durability andskid-resistance for public safety.

Street cuts through pavements are often required to repair buriedutilities, with subsequent backfilling of the trench and patching of theasphalt or concrete pavement. Often, the temperature or time to re-openthe street to traffic does not allow the installation of aproperly-constructed patch of like material of the pavement.Traditionally, “cold-mix” asphalt materials are frequently used as aquick, temporary trench patch. However, cold-mix patches are easilydamaged by snow-plows and often require frequent maintenance, until thepermanent pavement repair is made in the spring. Also, these cold-mixmaterials are subject to rutting under truck traffic, after theoccurrence of warm weather but before the permanent trench patch isinstalled. Thus, the present disclosure provides a fast-acting,economical, more-durable temporary pavement patch material & system.

In an embodiment of the present disclosure, a composition for patching atrench comprising between 70%-95% cementitious fly ash by weight;between 10% and 30% water by weight; and between 0.01% and 2% setretarder by weight, wherein the composition has compressive strength ofbetween 150 and 450 psi in 1 hour, a compressive strength of between 600and 1800 psi in 4 hours, and a set time of less than 40 minutes.

In some embodiments of the patch composition, no additional air contentis added, e.g., no air entraining agent is used. In other embodiments,the air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. For example, theamount of air within the composition helps control the final strength ofthe patch composition.

In some embodiments, the air content may be determined by the followingformula using wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$In other embodiments, the air content can be determined using ASTM C231.

In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur prior to addition of water, afteraddition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and possible filler) with water but prior to applying thecomposition to the void.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. Suitable cellular foam isavailable from a variety of sources, e.g., Cellular Concrete, LLC;Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and/or filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content, e.g., the desired finalcompressive strength. In some embodiments, the final air content of thecomposition will be between about 0.001% and about 15%, between about0.01% and about 13%, between about 0.1% and about 10%, between about1.0% and about 8%, between about 2% and about 6%, between about 0.1% andabout 5%, between about 0.1% and about 2%, between about 4% and about10%, between about 4% and about 8%. In some embodiments, the compositiondoes not contain any additional air content, i.e., the composition isnot purposefully air entrained.

In some embodiments, the final air content will be greater than 0.1%,greater than 1%, greater than 2%, greater than 4%, greater than 6%,greater than 8%, greater than 10%, greater than 12%.

In other embodiments, the final air content of the composition will beless than 15%, less than 13%, less than 10%, less than 8%, less than 6%,less than 4%, less than 2%, less than 1%, less than 0.1%, less than0.01%.

In an embodiment of the present disclosure, the cementitious fly ash isClass C fly ash as defined by ASTM C618 or the standards of a localagency. In other embodiments of the present disclosure, the cementitiousfly ash can have cementitious properties without qualifying as Class Cfly ash under ASTM C618 or an equivalent standard. A cementitious flyash of the present disclosure is a fly ash that sets (e.g., solidifiesto 4 psi) within about thirty minutes at a water content of 30% byweight when water and cementitious fly ash are the only ingredients.

In an embodiment of the present disclosure, a composition has betweenabout 60% and about 95% cementitious fly ash, between about 65% andabout 90% cementitious fly ash, between about 65% and about 85%cementitious fly ash, between about 70% cementitious fly ash and about80% cementitious fly ash, between about 60% and about 80% cementitiousfly ash, and between about 70% and about 90% cementitious fly ash.

In some embodiments of the present disclosure, a composition has lessthan about 95% cementitious fly ash, less than about 90% cementitiousfly ash, less than about 85% cementitious fly ash, less than about 80%cementitious fly ash, less than about 75% cementitious fly ash, lessthan about 70% cementitious fly ash, less than about 65% cementitiousfly ash or less than about 60% cementitious fly ash. In additionalembodiments of the present disclosure, the composition has greater thanabout 60% cementitious fly ash, greater than about 65% cementitious flyash, cementitious fly ash, greater than about 70% cementitious fly ash,greater than about 75% cementitious fly ash, greater than about 80%cementitious fly ash, greater than about 85% cementitious fly ash,greater than about 90% cementitious fly ash, or greater than about 95%cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. In an embodiment of the present disclosure, a composition hasa water content of between about 10% and about 45%, between about 15%and about 35%, between about 20% and about 30%, between about 10% andabout 30%, between about 10% and about 25%, between about 20% and about45%. In additional embodiments, a composition has greater than about 10%water, greater than about 20% water, greater than about 30% water,greater than about 40% water, or greater than about 50% water. In otherembodiments, a composition has less than about 55% water, less thanabout 45% water, less than about 35% water, less than about 25% water,less than about 20% water, less than about 15% water, or less than about10% water. Any water included with additional ingredients, e.g, aqueouswater retarders, foaming agents, etc. under the circumstancesencountered in the field by the inventors has been negligible incomparison to the primary batch water and therefore has not beenincluded in the above calculations. Depending on the actual watercontent of the additional ingredients used it may be necessary toconsider the additional water in the final water concentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, aggregate, or recycled versionthereof. Determination of the filler material can be based on economics,availability, city, county and/or state specifications, or on thedesired properties of the composition, e.g., desired setting time,flowability, or final compressive strength.

In an embodiment, a composition of the present disclosure will havebetween about 1% and about 40% filler, between about 5% and about 35%filler, between about 10% and about 30% filler, between about 15% andabout 25% filler, between about 1% and about 20%, between about 5% andabout 20%, between about 5% and about 15%, between about 30% and about40%. In certain embodiments, a composition of the present disclosurewill have less than about 50% filler, less than about 70% filler, lessthan about 60% filler, less than about 50% filler, less than about 40%filler, less than about 35% filler, less than about 30% filler, lessthan about 25% filler, less than about 20% filler, less than about 15%filler, less than about 10% filler, less than about 5% filler or lessthan about 3% filler. In still other embodiments, a composition of thepresent disclosure will have greater than about 10% filler, greater thanabout 15% filler, greater than about 20% filler, greater than about 25%filler, greater than about 30% filler, greater than about 35% filler, orgreater than about 40% filler.

Patch compositions will comprise a set retarder in some embodiments. Aset retarder is a compound capable of delaying the set time of thecomposition. An example of a set retarder may be citric acid or borax,or a combination thereof. In certain embodiments, the set retarder isliquid while in other embodiments the set retarder is a powder. Anappropriate set retarder will be well known to a person of ordinaryskill in the art.

In an embodiment, the concentration of set retarder is between about0.01% and about 3%, between about 0.01% and about 2% between about 0.05%and about 2.5%, between about 0.1% and about 2%, between about 0.5% andabout 1.5%, between about 0.0001% and about 1.0%. In some embodiments,the set retarder is greater than about 0.001%, is greater than about0.01% is greater than about 0.05%, is greater than about 0.1%, isgreater than about 0.5%, is greater than about 1.0%, is greater thanabout 1.5%, or is greater than about 2.0%. In certain embodiments, theset retarder is less than about 3.0%, less than about 2.5%, less thanabout 2.0%, less than about 1.5%, less than about 1.0%, less than about0.5%, less than about 0.3%, less than about 0.1%, less than about 0.01%,less than about 0.001%.

In some embodiments, the composition may further comprise a waterreducer. Water reducers may be used when a higher final strength isdesired at a specified density and fluidity. In some embodiments thewater reducer will be powder while in other embodiments it will be aliquid water reducer. In an embodiment, the water reducer is CHRYSO 256(high range) or 380 (midrange) or similar composition. A water reduceris a chemical (e.g., chemical composition) that allows a mixture tomaintain the same fluidity with less water or more fluidity with thesame amount of water.

In an embodiment, the concentration of the water reducer is betweenabout 0.01% and about 3%, between about 0.01% and about 2%, betweenabout 0.05% and about 2.5%, between about 0.1% and about 2%, betweenabout 0.5% and about 1.5%, between about 0.0001% and about 1.0%. In someembodiments, the water reducer is greater than about 0.001%, is greaterthan about 0.01% is greater than about 0.05%, is greater than about0.1%, is greater than about 0.5%, is greater than about 1.0%, is greaterthan about 1.5%, or is greater than about 2.0%. In certain embodiments,the water reducer is less than about 3.0%, less than about 2.5%, lessthan about 2.0%, less than about 1.5%, less than about 1.0%, less thanabout 0.5%, less than about 0.3%, less than about 0.1%, less than about0.01%, less than about 0.001%.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. In some embodiments, the settime of the composition is determined by measuring penetrationresistance with a pocket penetrometer (e.g., with a resistance of 4 psias typically used in standard ASTM WK 27337) or cement setting timestandard ASTM C403.

In an embodiment of the present disclosure, the set time for acomposition can be between about 10 minutes and about 50 minutes,between about 15 minutes and about 40 minutes, between about 15 minutesand about 30 minutes, between about 20 minutes hours and about 40minutes, between about 10 minutes and 30 minutes. In additionalembodiments, a composition has a set time of less than 50 minutes, ofless than about 40 minutes, of less than about 30 minutes, of less thanabout 20 minutes, of less than about 15 minutes. In other embodiments, acomposition has a set time of greater than about 10 minutes, of greaterthan about 20 minutes, of greater than about 25 minutes, of greater thanabout 30 minutes, of greater than about 35 minutes, of greater thanabout 40 minutes.

Compositions of the present disclosure will have a range of compressivestrengths at various times after the addition of a composition to a voiddepending on the desired properties of the composition.

In certain embodiments, the compressive strength is measured at 1 hour,2 hours, 4 hours, 1 day, 3 days, 7 days and 28 days where the 28 daymeasurement is considered the final compressive strength. In otherembodiments, the compressive strength is measured more often at smallerintervals or less often at larger intervals. In some embodiments, thecompressive strength is measured at 90 days. In an embodiment, thecompressive strength or bearing penetration or capacity resistance of acomposition is measured at 1 hour, 2 hours, 4 hours, 7 days, and 28 daysafter backfilling using ASTM WK 27337 or C403.

In an embodiment, the compressive strength (e.g., ASTM C495 and/or C31)of a composition of the present disclosure at 1 hour will be betweenabout 150 psi and about 450 psi, between about 200 psi and about 400psi, between about 250 psi and about 350 psi. In additional embodiments,the compressive strength of the composition at 1 hour will be greaterthan about 150 psi, will be greater than about 200 psi, will be greaterthan about 250 psi, will be greater than about 300 psi, will be greaterthan about 350 psi. In an embodiment, the compressive strength of thecomposition of the present disclosure will be less than about 450 psi at1 hour, less than about 400 psi at 1 hour, less than about 350 psi at 1hour, less than about 300 psi at 1 hour, less than about 250 psi at 1hour, less than about 250 psi at 1 hour.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 4 hours will be between about 600 psi and about1800 psi, 700 psi and about 1600 psi, between about 800 psi and about1400 psi, between about 600 psi and about 1000 psi, between about 1200psi and about 1800 psi. In additional embodiments, the compressivestrength of the composition at 4 hours will be greater than about 600psi, will be greater than about 800 psi, will be greater than about 1000psi, will be greater than about 1200 psi, will be greater than about1400 psi, will be greater than about 1600 psi. In an embodiment, thecompressive strength of a composition of the present disclosure at 4hours will be less than about 1800 psi, less than about 1600 psi, lessthan about 1400 psi, less than about 1200 psi, less than about 1000 psi,or less than about 800 psi, less than about 700 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 24 hours will be between about 2500 psi and about6000 psi, between about 3000 psi and about 5000 psi, between about 3500psi and about 4500 psi, between about 2500 psi and about 3500 psi,between about 4000 psi and about 6000 psi. In additional embodiments,the compressive strength of the composition at 24 hours will be greaterthan about 2500 psi, will be greater than about 3000 psi, will begreater than about 3500 psi, will be greater than about 4000 psi, willbe greater than about 4500 psi, will be greater than about 5000 psi, orwill be greater than about 5500 psi. In certain embodiments, thecompressive strength of the composition at 24 hours will be less thanabout 6000 psi, less than about 5500 psi, less than about 5000 psi, lessthan about 4500 psi, less than about 4000 psi, less than about 3500 psi,or less than about 3000 psi.

In certain embodiments of the present disclosure, a suitable compositioncan be defined by the water to fly ash ratio, e.g., when using nofiller, when using non-cementitious fly ash filler, or other suitablefiller like sand. The water to fly ash ratio will be a water tocementitious fly ash plus additional non-cementitious fly ash fillerratio.

In certain embodiments, a composition can have a range of water to flyash ratios depending on the water demand of the fly ash (or includedfiller), the desired flowability, the desired setting time and thedesired final compressive strength. In certain embodiments, the water tofly ash ratio of a composition (W/FA) is between about 0.15 and about0.25, between about 0.2 and about 0.6, between about 0.2 and about 0.5,between about 0.2 and about 0.4 or between about 0.25 and about 0.35. Inadditional embodiments, the water to fly ash ratio of a composition isgreater than about 0.2, greater than about 0.25, greater than about 0.3,greater than about 0.35 or greater than about 0.4. In other embodiments,the water to fly ash ratio is less than about 0.6, less than about 0.5,less than about 0.4, less than about 0.35, less than about 0.3, lessthan about 0.25 or less than about 0.2.

In certain embodiments of the present disclosure, a patch compositiondoes not include one or more of the following: does not include a waterreducer, does not include Portland cement, does not include a setretarder, does not include any cementitious material other thancementitious fly ash, does not include a filler, does not includeaggregate, does not include gravel, does not include CaCO₃ or lime otherthan that present in the cementitious fly ash and/or filler, or does notinclude sand. Furthermore, a composition of the present disclosure doesnot include native soils in some embodiments.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611or spread as determined by D6103.

The density in a patch composition is important in certain embodiments.In embodiments, a composition of the present disclosure has a unitweight of between about 110 pcf and about 150 pcf, of between about 120pcf and about 145 pcf, between about 125 pcf and about 135 pcf, betweenabout 115 pcf and about 140 pcf, between about 115 pcf and about 135pcf, between about 125 pcf and 150 pcf, between about 120 pcf and 150pcf. In other embodiments, the unit weight of a composition is greaterthan about 90 pcf, greater than about 100 pcf, greater than about 110pcf, greater than about 120 pcf, greater than about 130 pcf, greaterthan about 140 pcf, or greater than about 150 pcf. In still otherembodiments, a composition has a unit weight of less than about 160 pcf,of less than about 150 pcf, of less than about 140 pcf, of less thanabout 130 pcf, of less than about 120 pcf, of less than about 110 pcf,of less than about 100 pcf or of less than about 90 pcf.

The present disclosure also contemplates a method of determining atrench patch composition comprising: identifying at least one fly ashfor use in the composition; determining a water demand of each fly ashwithin the composition; calculating a water demand for the composition;determining a compressive strength for the composition; determining theamount of air content necessary for the composition to have acompressive strength of between 150 and 450 psi in 1 hour, a compressivestrength of between 600 and 1800 psi in 4 hours, and a set time of lessthan 40 minutes; determining the time necessary to fill the void; anddetermining the concentration of set retarder necessary to delay thecomposition from setting in less time than necessary to fill the void.

The present disclosure also discloses a method of patching a trench witha patch composition comprising: determining the time necessary to fillthe void; adding water and set retarder to a cementitious fly ash tomake a wet mixture, wherein the composition has a compressive strengthof between 150 and 450 psi in 1 hour, a compressive strength of between600 and 1800 psi in 4 hours, and a set time of less than 40 minutes; andadding the composition to the trench. In additional embodiments, themethod can further include adding a aggregate to the surface of thepatch prior to setting. The aggregate will provide texture or abrasion,resulting in increased traction for vehicles or pedestrians. Theaggregate may be sand, chips, crushed rock, or any material suitable forproviding texture and traction. In addition, the surface of the patchmay be squeegeed or broomed to provide texture either concurrent withthe addition of aggregate or in place of aggregate.

In an embodiment of the present disclosure, the basic dry components fora composition can be packaged in bags or buckets, for easy mixing ofsmall quantities by a contractor in the field with a wheelbarrow &shovel, an electric-drill & paddle-mixer for in-bucket mixing, or asmall portable concrete mixer. Depending on the application, thecombination of the dry ingredients in an embodiment can includecementitious fly ash only; cementitious fly ash and sand; cementitiousfly ash and gravel; or cementitious fly ash, sand and gravel. Inalternative embodiments, any combination of dry ingredients may beprovided in a prepackaged bag or bucket. A prepackaged composition mayalso include powder set retarder, e.g., borax. In addition, a separatebag of surface aggregate can be included for spreading over the surfaceof the composition prior to setting.

In alternative embodiments, the patch composition can be modified toprovide a permanent concrete pavement repair system.

Compositions for Use as Masonry Grout and Methods of Utilizing the Same

The present disclosure also discloses a masonry grout composition forfilling cores or cavities in traditional masonry construction. Whileusually added for structural reasons, grout can also increase: fireratings, security, acoustical performance, termite resistance, blastresistance, thermal storage capacity and anchorage capabilities. Masonrygrout may be used to structurally bond wall elements into a wall system,e.g., steel reinforcing bars to the masonry. In addition, grouted corescan increase the net cross-sectional area of concrete masonry and permitwalls to carry higher compressive, shear loads and lateral loads. Amasonry grout composition of the present disclosure replaces traditionalPortland-based cement grout by using cementitious fly ash.

In an embodiment, a masonry grout composition comprises between 0.0001%and 15% air by volume; between 70%-95% cementitious fly ash by weight;between 10% -30% water by weight, wherein the composition sets in lessthan 60 minutes and has a compressive strength of between 1500 psi and3000 psi after 28 days.

The air content of the compositions of the present disclosure will varydepending on the desired properties of the composition. In someembodiments, the air content may be determined by the following formulausing wet densities before and after the addition of air:

${{Air}\mspace{14mu}{content}} = \frac{\left( {{{Unit}\mspace{14mu}{Weights}_{{no}\mspace{14mu}{air}}} - {{Unit}\mspace{14mu}{Weight}_{air}}} \right) \times 100\%}{{Unit}\mspace{14mu}{Weight}_{{no}\mspace{14mu}{air}}}$

In other embodiments, the air content can be determined using ASTM C231.In certain embodiments, the air content is achieved by mixing an airentraining agent, i.e., a dry surfactant or liquid admixture into thecementitious fly ash and/or filler prior to addition of water. In theseembodiments, the air content may by uniformly distributed by mixingdirectly in a truck or by mixing in a commonly used agitation/mixingdevice. The mixing process can occur prior to addition of water, afteraddition of water or simultaneously with the addition of water.

In another embodiment, the air content is achieved by addition of an airentraining agent after mixture of the dry ingredients (cementitious flyash and filler) with water but prior to applying the composition to thevoid.

In specific embodiments, the air content may be achieved by adding apre-formed cellular foam, e.g., GEOFOAM SNP foam liquid concentrateavailable from Cellular Concrete, LLC., 7020 Snowdrift Road, Suite 102,Allentown, Pa. 18106 or 5916 McIntyre St, Golden, Colo. 80403. Thecellular foam may be pervious or non-pervious, and pre-foamed therebyreducing or alleviating the need to vigorously agitate the compositionto activate the air entraining agent. Any suitable foaming agent may beused that achieves the desired end properties as described herein, e.g.,an anionic foaming agent, a cationic foaming agent or a non-ionicfoaming agent. An example of a pervious foam is GEOFOAM SP. An exampleof a non-pervious foam is GEOFOAM SNP. Suitable cellular foam isavailable from a variety of sources, e.g., Cellular Concrete, LLC;Provoton Foam Concrete, 28 East Larkspur Lane, Bristol, Ill. 60512;Allied Foam Tech Corp., 146 Keystone Dr. Montgomeryville, Pa. 18936; andVermillion LLC and Associates, 2176 Sargent Daly Dr., Chattanooga, Tenn.37421. The choice of an appropriate cellular foam is within one of skillin the art and may be dictated by cost, environmental concerns, or theneed to meet the requirements of local or national agencies. In someembodiments, the foaming agent will conform to ASTM C869 and C796, inother embodiments the air entraining agent conforms to ASTM C260.

In some embodiments, the addition of cellular foam or similar airentraining agent may occur after the addition of water to thecementitious fly ash and filler immediately prior to the cementitiousmixture leaving a mixing truck, as the cementitious mixture leaves themixing truck (simultaneously) or after the cementitious mixture leavesthe mixing truck.

The amount of air entraining agent necessary for a given compositionwill vary with the desired air content. In some embodiments, the finalair content of the composition will be between about 0.001% and about15%, between about 0.01% and about 13%, between about 0.1% and about10%, between about 1.0% and about 8%, between about 2% and about 6%,between about 0.1% and about 5%, between about 0.1% and about 2%,between about 4% and about 10%, between about 4% and about 8%.

In some embodiments, the composition does not contain any additional aircontent, i.e., the composition is not purposefully air entrained.

In some embodiments, the final air content will be greater than 0.1%,greater than 1%, greater than 2%, greater than 4%, greater than 6%,greater than 8%, greater than 10%, greater than 12%.

In other embodiments, the final air content of the composition will beless than 15%, less than 13%, less than 10%, less than 8%, less than 6%,less than 4%, less than 2%, less than 1%, less than 0.1%, less than0.01%.

In an embodiment of the presently disclosure masonry grout composition,the cementitious fly ash is Class C fly ash as defined by ASTM C618 orthe standards of a local agency. In other embodiments of the presentdisclosure, the cementitious fly ash can have cementitious propertieswithout qualifying as Class C fly ash under ASTM C618 or an equivalentstandard. A cementitious fly ash of the present disclosure is a fly ashthat sets (e.g., solidifies to 4 psi) within about thirty minutes at awater content of 30% by weight when water and cementitious fly ash arethe only ingredients.

In an embodiment of the present disclosure, a masonry grout compositionhas between about 70% and about 95% cementitious fly ash, between about75% and about 90% cementitious fly ash, between about 80% and about 85%cementitious fly ash, between about 70% cementitious fly ash and about85% cementitious fly ash, between about 80% and about 95% cementitiousfly ash.

In some embodiments of the present disclosure, a composition has lessthan about 95% cementitious fly ash, less than about 90% cementitiousfly ash, less than about 85% cementitious fly ash, less than about 80%cementitious fly ash, less than about 75% cementitious fly ash, lessthan about 70% cementitious fly ash. In additional embodiments of thepresent disclosure, a masonry grout composition has greater than about70% cementitious fly ash, greater than about 75% cementitious fly ash,greater than about 80% cementitious fly ash, greater than about 85%cementitious fly ash, greater than about 90% cementitious fly ash.

In an embodiment of the presently disclosed composition, the water isstandard city potable water. In another embodiment, the water used inthe composition is substantially purified of additional minerals orother impurities. In still another embodiment of the present disclosure,the water is non-potable water. In additional embodiments, the water isselected based on its natural impurities, i.e., specific mineral contentlike calcium, magnesium, iron, or similar water minerals.

The water content of the presently disclosed composition may varydepending on desired flowability, setting time and final compressivestrength. In an embodiment of the present disclosure, a composition hasa the water content of between about 10% and about 30%, between about15% and about 25%, between about 10% and about 20%, between about 15%and about 30%. In additional embodiments, a composition has greater thanabout 10% water, greater than about 15% water, greater than about 20%water, greater than about 25% water, or greater than about 30% water. Inother embodiments, a composition has less than about 30% water, lessthan about 25% water, less than about 20% water, less than about 15%water, less than about 10% water. Any water included with additionalingredients, e.g., aqueous water retarders, foaming agents, etc. underthe circumstances encountered in the field by the inventors has beennegligible in comparison to the primary batch water and therefore hasnot been included in the above calculations. Depending on the actualwater content of the additional ingredients used it may be necessary toconsider the additional water in the final water concentrations.

In some embodiments of the present disclosure, a composition willinclude at least one filler. In additional embodiments, a compositionwill include only one filler, while in other embodiments, a compositionwill contain only two fillers. In still additional embodiments, acomposition will contain less than 3 fillers or less than 4 fillers. Afiller in the present disclosure can be additional fly ash, e.g., type Ffly ash as determined by ASTM C618 or equivalent standard. A filler canalso be non-specification grade non-cementitious fly ash, e.g., a flyash that does not meet the specifications determined by ASTM C618. Incertain embodiments a filler can be sand, bottom ash, quarry fines,soil, gravel and Portland cement, rubber, aggregate, or recycled versionthereof. Determination of the filler material can be based on economics,availability, city, county and/or state specifications, or on thedesired properties of the composition, e.g., desired setting time,flowability, or final compressive strength.

In an embodiment, a composition of the present disclosure will havebetween about 20% and about 60% filler, between about 25% and about 55%filler, between about 30% and about 50% filler, between about 20% andabout 40% filler, between about 20% and about 30%, between about 40% andabout 60%, between about 30% and about 40% filler. In certainembodiments, a composition of the present disclosure will have less thanabout 60% filler, less than about 55% filler, less than about 50%filler, less than about 45% filler, less than about 40% filler, lessthan about 35% filler, less than about 30% filler, less than about 25%filler. In still other embodiments, a composition of the presentdisclosure will have greater than about 20% filler, greater than about25% filler, greater than about 30% filler, greater than about 35%filler, greater than about 40% filler, greater than about 50% filler, orgreater than about 55% filler.

Masonry grout compositions will comprise a set retarder in someembodiments. A set retarder is a compound capable of delaying the settime of the composition. In certain embodiments, delaying the set timeis necessary to allow a masonry grout composition to completely fill avoid before setting. An example of a set retarder may be citric acid orborax, or a combination thereof. In certain embodiments, the setretarder is liquid while in other embodiments the set retarder is apowder. An appropriate set retarder will be well known to a person ofordinary skill in the art.

In an embodiment, the concentration of set retarder is between about0.01% and about 3%, between about 0.01% and about 2% between about 0.05%and about 2.5%, between about 0.1% and about 2%, between about 0.5% andabout 1.5%, between about 0.0001% and about 1.0%. In some embodiments,the set retarder is greater than about 0.001%, is greater than about0.01% is greater than about 0.05%, is greater than about 0.1%, isgreater than about 0.5%, is greater than about 1.0%, is greater thanabout 1.5%, or is greater than about 2.0%. In certain embodiments, theset retarder is less than about 3.0%, less than about 2.5%, less thanabout 2.0%, less than about 1.5%, less than about 1.0%, less than about0.5%, less than about 0.3%, less than about 0.1%, less than about 0.01%,less than about 0.001%.

Compositions of the present disclosure will have a range of possible settimes based on the desired application. In some embodiments, the settime of the masonry grout composition is determined by measuringpenetration resistance with a pocket penetrometer (e.g., with aresistance of 4 psi as typically used in standard ASTM WK 27337) orcement setting time standard ASTM C403. In an embodiment of the presentdisclosure, the set time for a composition can be between about 10minutes and about 60 minutes, between about 15 minutes and about 50minutes, between about 15 minutes and about 30 minutes, between about 20minutes hours and about 40 minutes, between about 10 minutes and 30minutes, between about 30 minutes and 60 minutes. In additionalembodiments, a composition has a set time of less than about 60 minutes,of less than about 50 minutes, of less than about 40 minutes, of lessthan about 30 minutes, of less than about 20 minutes, of less than about1 hour. In other embodiments, a composition has a set time of greaterthan about 10 minutes, of greater than about 20 minutes, of greater thanabout 25 minutes, of greater than about 30 minutes, of greater thanabout 35 minutes, of greater than about 40 minutes, of greater thanabout 50 minutes, of greater than about 60 minutes.

Masonry grout compositions of the present disclosure will have a rangeof compressive strengths at various times after the addition of acomposition to a void depending on the desired properties of thecomposition.

In certain embodiments, the compressive strength is measured at 1 hour,2 hours, 4 hours, 1 day, 3 days, 7 days and 28 days where the 28 daymeasurement is considered the final compressive strength. In otherembodiments, the compressive strength is measured more often at smallerintervals or less often at larger intervals. In some embodiments, thecompressive strength is measured at 90 days. In an embodiment, thecompressive strength or bearing penetration or capacity resistance of acomposition is measured at 1 hour, 2 hours, 4 hours, 7 days, and 28 daysafter backfilling using ASTM WK 27337 or C403. In additionalembodiments, the flexural strength is measured using ASTM C78.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 1 hour will be between about 150 psi and about 450psi, between about 200 psi and about 400 psi, between about 250 psi andabout 350 psi. In additional embodiments, the compressive strength ofthe composition at 1 hour will be greater than about 150 psi, will begreater than about 200 psi, will be greater than about 250 psi, will begreater than about 300 psi, will be greater than about 350 psi. In anembodiment, the compressive strength of the composition of the presentdisclosure will be less than about 450 psi at 1 hour, less than about400 psi at 1 hour, less than about 350 psi at 1 hour, less than about300 psi at 1 hour, less than about 250 psi at 1 hour, less than about250 psi at 1 hour.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 1 day will be between about 500 psi and about 1800psi, 700 psi and about 1600 psi, between about 800 psi and about 1400psi, between about 600 psi and about 1000 psi, between about 1200 psiand about 1800 psi. In additional embodiments, the compressive strengthof the composition at 1 day will be greater than about 500 psi, will begreater than about 700 psi, will be greater than about 1000 psi, will begreater than about 1200 psi, will be greater than about 1400 psi, willbe greater than about 1600 psi. In an embodiment, the compressivestrength of a composition of the present disclosure at 1 day will beless than about 1800 psi, less than about 1600 psi, less than about 1400psi, less than about 1200 psi, less than about 1000 psi, or less thanabout 800 psi, less than about 700 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 7 days will be between about 1000 psi and about2000 psi, 1100 psi and about 1800 psi, between about 1200 psi and about1600 psi, between about 100 psi and about 1500 psi, between about 1500psi and about 2000 psi. In additional embodiments, the compressivestrength of the composition at 7 days will be greater than about 500psi, will be greater than about 700 psi, will be greater than about 1000psi, will be greater than about 1200 psi, will be greater than about1400 psi, will be greater than about 1600 psi, will be greater than 1800psi. In an embodiment, the compressive strength of a composition of thepresent disclosure at 7 days will be less than about 2000 psi, less thanabout 1800 psi, less than about 1600 psi, less than about 1400 psi, lessthan about 1200 psi, less than about 1000 psi, or less than about 800psi, less than about 700 psi.

In an embodiment, the compressive strength of a composition of thepresent disclosure at 28 day will be between about 1500 psi and about3000 psi, between about 3000 psi and about 5000 psi, between about 3500psi and about 4500 psi, between about 2500 psi and about 3500 psi,between about 4000 psi and about 6000 psi. In additional embodiments,the compressive strength of the composition at 28 days will be greaterthan about 2500 psi, will be greater than about 3000 psi, will begreater than about 3500 psi, will be greater than about 4000 psi, willbe greater than about 4500 psi, will be greater than about 5000 psi, orwill be greater than about 5500 psi. In certain embodiments, thecompressive strength of the composition at 28 days will be less thanabout 6000 psi, less than about 5500 psi, less than about 5000 psi, lessthan about 4500 psi, less than about 4000 psi, less than about 3500 psi,or less than about 3000 psi.

In certain embodiments of the present disclosure, a suitable masonrygrout composition can be defined by the water to fly ash ratio, e.g.,when using no filler, when using non-cementitious fly ash filler, orother suitable filler like ground rubber. In certain embodiments, thewater to fly ash ratio will be a water to cementitious fly ash plusadditional non-cementitious fly ash filler ratio.

In certain embodiments, a composition can have a range of water to flyash ratios depending on the water demand of the fly ash (or includedfiller), the desired flowability, the desired setting time and thedesired final compressive strength. In certain embodiments, the water tofly ash ratio of a composition (W/FA) is between about 0.10 and about0.30, between about 0.15 and about 0.25, between about 0.2 and about0.25, between about 0.2 and about 0.3, between about 0.1 and about 0.2or between about 0.05 and about 0.2. In additional embodiments, thewater to fly ash ratio of a composition is greater than about 0.1,greater than about 0.15, greater than about 0.2, greater than about0.25. In other embodiments, the water to fly ash ratio is less thanabout 0.35, less than about 0.3, less than about 0.25, less than about0.2, less than about 0.15, less than about 0.1.

In certain embodiments of the present disclosure, a masonry groutcomposition does not include one or more of the following: does notinclude a water reducer, does not include Portland cement, does notinclude a set retarder, does not include any cementitious material otherthan cementitious fly ash, does not include a filler, does not includeaggregate, does not include gravel, does not include CaCO₃ or lime otherthan that present in the cementitious fly ash and/or filler, or does notinclude sand. Furthermore, a composition of the present disclosure doesnot include native soils in some embodiments.

In certain embodiments, the flowability of a composition can bedetermined by a slump test C143 or a slump flow as determined by C1611or spread as determined by D6103. In some embodiments, the masonry groutcomposition meets or exceeds the performance requirements of ASTM C476.

The density of the masonry grout composition is important in certainembodiments. In embodiments, a composition of the present disclosure hasa unit weight of between about 110 pcf and about 150 pcf, of betweenabout 120 pcf and about 145 pcf, between about 125 pcf and about 135pcf, between about 115 pcf and about 140 pcf, between about 115 pcf andabout 135 pcf, between about 125 pcf and 150 pcf, between about 120 pcfand 150 pcf. In other embodiments, the unit weight of a composition isgreater than about 90 pcf, greater than about 100 pcf, greater thanabout 110 pcf, greater than about 120 pcf, greater than about 130 pcf,greater than about 140 pcf, or greater than about 150 pcf. In stillother embodiments, a composition has a unit weight of less than about160 pcf, of less than about 150 pcf, of less than about 140 pcf, of lessthan about 130 pcf, of less than about 120 pcf, of less than about 110pcf, of less than about 100 pcf or of less than about 90 pcf.

The present disclosure also contemplates a method of determining amasonry grout for construction comprising: identifying at least one flyash for use in the composition; determining a water demand of each flyash within the composition; calculating a water demand for thecomposition; determining a compressive strength for the composition;determining the amount of air content necessary for the composition toset is less than 60 minutes and has a compressive strength of between100 and 500 psi after 1 hour and 2500 and 6000 psi after 24 hours.

The determination of suitable fly ash, water demand, compressivestrength, air content, density, time to finish the construction project,and the concentration of set retarder can be accomplished as discussedelsewhere in this application.

The present disclosure also contemplates a method of filling a voidbetween retaining walls with masonry grout composition comprising:mixing cementitious fly ash and filler to a predetermined ratio; andadding water to the mix of cementitious fly ash and filler to make a wetmixture, wherein the composition sets is less than 60 minutes and has acompressive strength of between 100 and 500 psi after 1 hour and 2500and 6000 psi after 24 hours.

Although embodiments of the present disclosure have been described withrespect to backfilling a trench to prevent ice lens formation andquicker return to use of the backfilled area, it should be appreciatedthat the principles of the present disclosure can also be applied tofilling voids due to pipe abandonment, annular spaces, undercut areas,and other void filling applications. It should also be appreciated thatthe principles of the present disclosure can also be applied toproviding structural support for utilities, replacement of unstablesubgrade during pavement repairs and similar applications.

The foregoing description of the exemplary embodiments of the disclosurehas been presented for the purposes of illustration and description.They are not intended to be exhaustive or to limit the disclosure to theprecise forms disclosed. Many modifications and variations are possiblein light of the above teaching. It is intended that the scope of thedisclosure be limited not with this detailed description, but rather bythe claims appended hereto.

EXAMPLES

The weight of the ingredients in the following examples have beennormalized to provide one cubic yard of final composition. That is, theactual amounts used in the examples have been proportionally increasedor decreased based on the final volume achieved to one cubic yard. Forexample, if a laboratory batch of 25 lbs cementitious fly ash and 8 lbsof water yielded a final volume of 0.01 cubic yard, the example would bereported below as 2,500 lbs fly ash and 800 lbs water.

Example 1

A 1.5:1 (non-cementitious/cementitious) mix composition of the followingcomponents was prepared using a mixing truck: 685 lbs of cementitiousfly ash ASTM C618 class C from Excel Energy Pawnee Station; 1031 lbs ofnon-cementitious fly ash from Excel Energy Cherokee Station; 652 lbs ofcity water; and 4.7 cubic feet of cellular foam from GEOFOAM SNP(synthetic non-permeable foam), C796 and C869.

The composition had the following physical properties: Time to set wasapproximately 15 minutes; the spread (ASTM D6103) was 9.5 inches; theslump-cone spread was approximately 26 inches; the air content was 18%;the unit weight was 88 pcf; and the water/fly ash ratio was 0.38.

The composition has the following compressive strengths: 30 psi at fourhours; 40 psi at one day; 166 psi at seven days; and 274 psi at 28 days.The composition had a removability modulus of 1.42.

Example 2

A 1.5:1 (non-cementitious/cementitious) mix composition of the followingcomponents was prepared using a mixing truck: 644 lbs of cementitiousfly ash ASTM C618 class C from Excel Energy Pawnee Station; 970 lbs ofnon-cementitious fly ash from Excel Energy Cherokee Station; 613 lbs ofcity water; and 6.1 cubic feet of cellular foam from GEOFOAM SNP(synthetic non-permeable foam), C796 and C869.

The composition had the following physical properties: Time to set wasapproximately 15 minutes; the spread (ASTM D6103) was 14 inches; theslump-cone spread was approximately 35 inches; the air content was 23%;the unit weight was 83 pcf; and the water/fly ash ratio was 0.38.

The composition has the following compressive strengths: 19 psi at fourhours; 32 psi at one day; 91 psi at seven days; and 151 psi at 28 days.The composition had a removability modulus of 0.96.

Example 3

A 2:1 (non-cementitious/cementitious) mix composition of the followingcomponents was prepared in a laboratory: 572 lbs of cementitious fly ashASTM C618 class C from Excel Energy Pawnee Station; 1145 lbs ofnon-cementitious fly ash from Excel Energy Cherokee Station; 687 lbs ofcity water; and 4 cubic feet of cellular foam from GEOFOAM SNP(synthetic non-permeable foam), C796 and C869.

The composition had the following physical properties: The spread (ASTMD6103) was 10 inches; the slump-cone spread was approximately 26 inches;the air content was 15%; the unit weight was 86 pcf; and the water/flyash ratio was 0.40.

The composition has the following compressive strengths: 22 psi at sevendays; and 142 psi at 28 days. The composition had a removability modulusof 0.99.

Example 4

A 3:1 (non-cementitious/cementitious) mix composition of the followingcomponents was prepared in the laboratory: 390 lbs of cementitious flyash ASTM C618 class C from Excel Energy Pawnee Station; 1171 lbs ofnon-cementitious fly ash from Excel Energy Cherokee Station; 734 lbs ofcity water; and 4.1 cubic feet of cellular foam from GEOFOAM SNP(synthetic non-permeable foam), C796 and C869.

The composition had the following physical properties: The spread (ASTMD6103) was 10 inches; the slump-cone spread was approximately 26 inches;the air content was 15%; the unit weight was 85 pcf; and the water/flyash ratio was 0.47.

The composition has the following compressive strengths: 55 psi at sevendays; and 123 psi at 28 days. The composition had a removability modulusof 0.90.

Example 5

A composition of the following components was prepared in thelaboratory: 732 lbs of cementitious fly ash ASTM C 618 class C fromExcel Energy Pawnee Station; 932 lbs of non-cementitious fly ash fromExcel Energy Cherokee Station; 699 lbs of city water; and 4.9 cubic feetof cellular foam from GEOFOAM SNP (synthetic non-permeable foam), C796and C869.

The composition had the following physical properties: The spread (ASTMD6103) was 11 inches; the slump-cone spread was approximately 28 inches;the air content was 18.2%; the unit weight was 87.5 pcf; and thewater/fly ash ratio was 0.42.

The composition has the following compressive strengths: 5 psi at fourhours; 38 psi at one day; 126 psi at seven days; and 157 psi at 28 days.The composition had a removability modulus of 1.06.

Example 6

In example 6, the following compositions were prepared for comparison asdisplayed in Table 2 and 3.

TABLE 2 The comparison of 9 different compositions with values in poundsper cubic yard unless otherwise indicated, e.g., air. Additional Cemen-Non- Filler Mix titious cementitious (e.g., % No. fly ash fly ash Sand)Water Total Air 1 Truck 685 1031 652 2368 18 2 Truck 644 970 613 2227 233 Lab 572 1145 687 2404 15 4 Lab 390 1171 734 2295 15 5 Lab 732 932 6992363 18 6 Lab 1350 405 1755 46 7 Lab 831 249 1080 67 8 Lab 1170 585 175540 9 Lab 720 360 1080 63

TABLE 3 Is an extension of Table 2 with the same compositions as Table 2but with values in percent by weight and including the 28 daycompressive strength data and RE for each composition. Addi- 28 day Non-tional Com- Cemen- cemen- Filler pressive Mix titious titious (e.g., %Strength No. fly ash fly ash Sand) Water Air (PSI) RE 1 Truck 29% 44% 0%28% 18 275 1.42 2 Truck 29% 44% 0% 28% 23 151 0.96 3 Lab 24% 48% 0% 29%15 142 0.99 4 Lab 17% 51% 0% 32% 15 123 0.90 5 Lab 31% 39% 0% 30% 18 1571.06 6 Lab 77%  0% 0% 23% 46 552 1.29 7 Lab 77%  0% 0% 23% 67 120 0.29 8Lab 67%  0% 0% 33% 40 355 1.00 9 Lab 67%  0% 0% 33% 63 81 0.25

Mix numbers 1 through 5 of Example 6 (e.g., Table 1 and Table 2) arecompositions comprising cementitious fly ash, non-cementitious fly ash,water and cellular foam to provide air content. Mix numbers 6 through 9are compositions containing no filler, no non-cementitious fly ash orotherwise, with water and cellular foam.

Example 7

Compressive strength testing for two types of cellular annular groutswere performed, one with Portland cement, the others with Class C flyash (no Portland cement), with and without water reducers. Sufficientcellular foam was added to achieve the project specified density of 55pcf, +/5 pcf; the minimum strength was specified as 300 psi at 28 days.Borax was added for sufficient set-retardation in mix numbers 2, 4 and5. The test results are summarized in table 4 below. Mix number 1 ofTable 4 is traditional Portland cement.

TABLE 4 Comparison of densities and compressive strength for fivedifferent annular grout compositions. Mix Density 7-day 28-day No.Material description (pcf) (psi) (psi) 1 Traditional Portland Cement53.3 550 544 2 Class C fly ash, with a water 55.0 560 586 retarder andBorax as a set retarder 3 50% Portland (dry ingredient — 290 — weight,50% Type F fly ash (dry ingredient weight) 4 Class C fly ash with boraxas a 52.2 252 489 set retarder 5 Class C fly ash with borax as a 47.0238 305 set retarder

Example 8

The compressive strength of different compositions of the presentdisclosure were tested at 1 day, 3 days, 7 days, and 28 days. As shownin Table 5, cementitious fly ash compositions of the present disclosureperform similarly to traditional Portland cement at lower water tocementitious material, i.e., fly ash, ratios.

TABLE 5 Cementitious fly ashes can perform similar to traditionalPortland cement at lower water to Cementitious material ratios. MixWater to Fly Ash 1 Day 3 Day 7-day 28-day No. Ratio (psi) (psi) (psi)(psi) 1 Pawnee Cementitious 2540 3890 4620 5710 Fly Ash 0.21 W/FA 2Pawnee Cementitious 2490 4270 4870 6190 Fly Ash 0.23 W/FA 3 PawneeCementitious 900 1060 1330 2015 Fly Ash 0.45 W/FA 4 Pawnee Cementitious300 800 990 1480 Fly Ash 0.50 W/FA 5 Holcim Cementitious 1380 4560 64305440 Fly Ash 0.45 W/FA 6 Holcim Cementitious 1050 3710 5440 8040 Fly Ash0.50 W/FA

Example 9

The effect of a set retarder, i.e., borax, was tested on compositions ofthe present disclosure. As shown in Table 6, the effect of borax, bypercent, are displayed with time of set in minutes and time to achieve63 psi in minutes for a 0.25 W/FA composition for use in pavementpatching. The borax dosage is expressed as a percentage of the fly ashweight. The 63 psi (4.5 tons/square-foot) gives an indication of whencars and light trucks could drive over the patch, without damage to thesurface or breaking the slab in flexure. The compressive strengthrequired for heavy trucks will vary based on municipalities and stateregulations. For example, one municipality requires 1800 psi and theColorado Department of Transportation requires 2500 psi for traditionalconcrete prior to opening to traffic.

TABLE 6 The effectiveness of a set retarder on different compositionsfor use as a pavement patch Mix % Set Time Time to 63 Ratio of 63 psi/No. Borax (min) psi (min) Set Time 1 0.0 4-5 7 1.6 2 0.1 7 10 1.4 3 0.212 — — 4 0.25 19 32 1.7 5 0.3 30 42 1.4 6 0.4 70 127 1.8

Example 10

The amount of chemical shrinkage was tested by comparing two differentwater to cement ratios for traditional Portland cement (Mix. Nos. 1 and2) with two different water to fly ash ratios of the present disclosure(Mix Nos. 3 and 4). Chemical shrinkage is the volumetric change in acomposition that occurs at the time of composition set, i.e.,transitioning from fluid to solid. Volume is measured when thecomposition remains flowable and again immediately after setting. Thechange in volume reflects the % chemical shrinkage. As shown in Table 7,traditional Portland cement compositions undergo a substantial chemicalshrinkage, e.g., Mix Nos. 1 and 2 of Table 7. By comparison,compositions of the present disclosure have dramatically reducedchemical shrinkage, e.g., Mix Nos. 3 and 4. Also shown in Table 7 is theeffect even a small change in water to cement ratio has on the %chemical shrinkage. For example, in Mix No. 1 of Table 7, a 0.45 waterto cement ratio has a % chemical shrinkage of 1.22. A change to 0.50water to cement mixture results in a % chemical shrinkage of 2.02, see,e.g., Mix No. 2 of Table 7. By contrast, a change from 0.22 water to flyash ratio to 0.50 water to fly ash ratio only results in a change of0.02% chemical shrinkage, compare Mix Nos. 3 and 4 of Table 7.

TABLE 7 Chemical shrinkage of traditional Portland cement compared withcompositions of the present disclosure. Mix % Chemical No. CompositionShrinkage 1 Traditional Portland Cement 1.22% Water to Cement Ratio =0.45 2 Traditional Portland Cement 2.02% Water to Cement Ration = 0.50 3Composition of the Present Disclosure 0.03% Water to Fly Ash Ratio (nofiller) = 0.22 4 Composition of the Present Disclosure 0.05% Water toFly Ash Ratio (no filler) = 0.50

Example 11

The amount of drying shrinkage was tested by comparing Portland cement(Mix. Nos. 1) with two different water to fly ash ratios of the presentdisclosure (Mix Nos. 2 and 3). Drying shrinkage is the volumetric changein a composition that occurs from the time of setting to 28 days. Volumeis measured when after the composition sets and again at 28 days. Thechange in volume reflects the % drying shrinkage as shown in Table 8.

TABLE 8 Drying shrinkage of traditional Portland cement compared withcompositions of the present disclosure. Mix % Drying No. CompositionShrinkage 1 Traditional Portland-cement concrete 0.04% to 0.06% 2 Ratioof Cementitious Fly Ash and 0.002% Water = 0.21 3 Ratio of CementitiousFly Ash and Water 0.001% (Aggregate added to 50% by volume) = 0.23

What is claimed is:
 1. A composition for patching pavement consistingessentially of: between 5% and 20% air by volume; between 65% and 90%Class C fly ash by weight; and between 16% and 30% water by weight; thecomposition having a time to set of less than 40 minutes, a compressivestrength of between 150 and 450 PSI in one hour, and a compressivestrength of between 600 and 1800 PSI in four hours.
 2. The compositionof claim 1, wherein the air is between 5% and 10% by volume of thecomposition.
 3. The composition of claim 1, wherein the Class C fly ashis between 70% and 85% by weight of the composition.
 4. The compositionof claim 1, wherein the water is between 16% and 23% by weight of thecomposition.
 5. The composition of claim 1, wherein the water is between23% and 30% by weight of the composition.
 6. The composition of claim 1,wherein the set time is less than 20 minutes.
 7. The composition ofclaim 1, wherein the set time is less than 15 minutes.
 8. Thecomposition of claim 1, wherein the removability modulus is less than1.5 after 28 days.
 9. The composition of claim 1, wherein the air isbetween 10% and 15% by volume; the Class C fly ash is between 74% and80% by weight; and the water is between 20% and 26% by weight.
 10. Thecomposition of claim 1 or 9, wherein the volume of air results from anair entraining agent.
 11. The composition of claim 10, wherein the airentraining agent is a cellular foam.
 12. A composition for patchingpavement consisting essentially of: between 5% and 20% air by volume;between 65% and 90% of Class C fly ash by weight; between 16% and 30%water by weight; between 0.1% and 0.5% set retarder by weight; thecomposition having a time to set of less than 40 minutes, a compressivestrength of between 150 and 450 PSI in one hour, and a compressivestrength of between 600 and 1800 PSI in four hours.
 13. A pavement patchconsisting essentially of: between 5% and 20% air by volume; between 65%and 90% Class C fly ash by weight; and between 16% and 30% water byweight; the pavement patch having a compressive strength of between 150and 450 PSI in one hour, and a compressive strength of between 600 and1800 PSI in four hours; and the pavement patch having an aggregate onits surface.
 14. The pavement patch of claim 13, wherein the aggregateis between 1 and 2 pounds per square yard of the surface of the pavementpatch.
 15. A composition for patching pavement consisting essentiallyof: between 5% and 10% air by volume; between 20% and 50% Class C flyash by weight; between 40% and 70% filler by weight; between 10% and 15%water by weight; the composition having a set time of less than 40minutes, a compressive strength of between 150 and 450 PSI in one hour,and a compressive strength of between 600 and 1800 PSI in four hours.16. The composition of claim 15, wherein the filler is sand.